Digital SAT Flashcards: Math, Grammar & Words in Context

Practice Digital SAT math formulas, grammar rules, transitions, and words in context with original, installable flashcards built for active recall.

Mayelana naleli qoqo

Digital SAT Flashcards: Math, Grammar & Words in Context

Practice the recall-worthy foundations behind all eight current SAT content domains: math formulas and setup cues, grammar and punctuation rules, transition logic, rhetorical choices, evidence checks, and high-utility words used in original sentence contexts. The 300 cards are ready to install and review offline.

What the cards practice

The deck maps short rule or task cues to a rule, distinction, formula, or setup. Original sentence contexts map to tested word meanings and grammar decisions. Original transition microcontexts name each transition and ask for the relationship it signals. Selected representation-to-interpretation prompts cover ideas such as slope as a rate of change and a residual as actual minus predicted. A few reverse prompts are included when recall in both directions prevents a common setup error.

What is deliberately left out

This is not a bank of SAT questions. It leaves out full passages, timed-test simulation, answer-choice elimination drills, copied questions, answer keys, mark schemes, official diagrams, arbitrary vocabulary lists, formula-symbol permutations, and automatic reversal of every fact. Use College Board's official practice for full reasoning, timing, and the adaptive test experience.

Coverage and learning order

Reading and Writing covers Information and Ideas, Craft and Structure, Expression of Ideas, and Standard English Conventions. Math covers Algebra, Advanced Math, Problem-Solving and Data Analysis, and Geometry and Trigonometry. The 15 transition microcontexts stay in their fixed Expression of Ideas slots. Prerequisites appear before dependent ideas inside each topic. Related variants are separated by unrelated cards, while long-term spacing and interleaving stay with the review scheduler.

Scope, provenance, and reuse

The current College Board assessment framework and content-domain pages were used only as a scope and fact-check map. The prompts, answers, microcontexts, examples, selection, organization, sequence, metadata, and generated cover are independently written. Public pages from three current study tools were reviewed only to compare learner expectations; no competitor cards or examples were copied.

The Common knowledge · CC0 1.0 label applies to the original wording, examples, organization, metadata, and generated cover to the extent applicable rights exist. It does not claim ownership of mathematical facts, grammar rules, SAT domain names, College Board names, or third-party source material.

Source review date: September 1, 2026.

This deck is independent and unofficial. It is not affiliated with, endorsed by, or approved by College Board. No exam questions, mark schemes, or official specifications text were copied; see College Board's official SAT content requirements.

Amakhadi akuleli qoqo

  1. Ikhadi 1

    Umbuzo

    Central idea of a passage?

    Impendulo

    The passage's main claim or controlling point. It should cover the whole passage, not one striking detail.

  2. Ikhadi 2

    Umbuzo

    The shade trees mitigated the midday heat. Meaning of “mitigated”?

    Impendulo

    Reduced. The trees made the heat less severe.

  3. Ikhadi 3

    Umbuzo

    The first plan was affordable. However, it took twice as long. What relationship does “However” signal?

    Impendulo

    Contrast. The second statement differs from or qualifies the first.

  4. Ikhadi 4

    Umbuzo

    Three standard joins for two independent clauses?

    Impendulo

    A period, a semicolon, or a comma plus a coordinating conjunction. Each side must be a complete sentence.

  5. Ikhadi 5

    Umbuzo

    Best supporting detail?

    Impendulo

    The detail that most directly proves the claim. Relevance matters more than how vivid or surprising it is.

  6. Ikhadi 6

    Umbuzo

    A second archive corroborated the diary's date. Meaning of “corroborated”?

    Impendulo

    Confirmed with supporting evidence.

  7. Ikhadi 7

    Umbuzo

    Every member of set A is even. Nine is odd; therefore, nine is not in set A. What relationship does “therefore” signal?

    Impendulo

    Conclusion from a reason. The final statement follows logically from the stated premises.

  8. Ikhadi 8

    Umbuzo

    Introductory dependent clause before a main clause?

    Impendulo

    Use a comma after the dependent clause. Example: “Although rain fell, the match continued.”

  9. Ikhadi 9

    Umbuzo

    Valid inference?

    Impendulo

    A conclusion that must follow, or that most reasonably follows, from the stated evidence. Avoid assumptions the text never supports.

  10. Ikhadi 10

    Umbuzo

    The team called its result tentative until replication. Meaning of “tentative”?

    Impendulo

    Provisional or not yet certain.

  11. Ikhadi 11

    Umbuzo

    Several materials block sound. For example, thick felt absorbs echoes. What relationship does “For example” signal?

    Impendulo

    Illustration. The second statement gives a specific case of the broader point.

  12. Ikhadi 12

    Umbuzo

    Singular subject with an intervening prepositional phrase?

    Impendulo

    Use a singular verb. Example: “The box of samples is sealed.” The phrase “of samples” does not change the subject.

  13. Ikhadi 13

    Umbuzo

    Strongest textual evidence?

    Impendulo

    The quotation or detail that most directly supports the target claim, with the fewest extra assumptions.

  14. Ikhadi 14

    Umbuzo

    The error had a negligible effect on the total. Meaning of “negligible”?

    Impendulo

    So small that it is not important.

  15. Ikhadi 15

    Umbuzo

    The first route avoids steep hills. Similarly, the second stays nearly level. What relationship does “Similarly” signal?

    Impendulo

    Similarity. The second statement matches the first in a relevant way.

  16. Ikhadi 16

    Umbuzo

    Opening modifier placement?

    Impendulo

    Place the noun being modified immediately after the opening phrase. Example: “Walking home, Lena noticed the mural.”

  17. Ikhadi 17

    Umbuzo

    Quantitative evidence for a claim?

    Impendulo

    Use the value, comparison, or trend that directly tests the claim, including the correct units and baseline.

  18. Ikhadi 18

    Umbuzo

    The lab used a conventional method before testing a new one. Meaning of “conventional”?

    Impendulo

    Traditional or commonly accepted.

  19. Ikhadi 19

    Umbuzo

    Mira checked the figures. Meanwhile, Omar revised the caption. What relationship does “Meanwhile” signal?

    Impendulo

    Simultaneous events. The second event happens at the same time as the first.

  20. Ikhadi 20

    Umbuzo

    Singular possessive noun?

    Impendulo

    Usually add apostrophe + s. Example: “the scientist's notebook.”

  21. Ikhadi 21

    Umbuzo

    Trend in a table or graph?

    Impendulo

    State what changes, in which direction, and across which interval. Do not turn a pattern into a cause without evidence.

  22. Ikhadi 22

    Umbuzo

    The essay offered a novel explanation for the pattern. Meaning of “novel”?

    Impendulo

    New or original in this context.

  23. Ikhadi 23

    Umbuzo

    The device was old. Nevertheless, it performed reliably. What relationship does “Nevertheless” signal?

    Impendulo

    Concession. The second statement remains true despite the limitation in the first.

  24. Ikhadi 24

    Umbuzo

    Parallel items in a series?

    Impendulo

    Use the same grammatical form for each item. Example: “to collect, analyze, and report data.”

  25. Ikhadi 25

    Umbuzo

    Claim stronger than the evidence?

    Impendulo

    Qualify the claim. Limited evidence can support “may” or “suggests,” not an absolute conclusion.

  26. Ikhadi 26

    Umbuzo

    Her account is plausible because it matches the records. Meaning of “plausible”?

    Impendulo

    Reasonable or believable.

  27. Ikhadi 27

    Umbuzo

    The plan cuts costs. Moreover, it shortens delivery time. What relationship does “Moreover” signal?

    Impendulo

    Addition. The second statement adds a related supporting point.

  28. Ikhadi 28

    Umbuzo

    Colon before an explanation or list?

    Impendulo

    Use it only after a complete independent clause. Example: “The kit needs three items: tape, gloves, and labels.”

  29. Ikhadi 29

    Umbuzo

    Claim versus evidence?

    Impendulo

    A claim is the point being argued; evidence is the information used to support it.

  30. Ikhadi 30

    Umbuzo

    The memo's ambiguous wording allowed two readings. Meaning of “ambiguous”?

    Impendulo

    Open to more than one interpretation.

  31. Ikhadi 31

    Umbuzo

    The team didn't replace the sensor. Instead, it recalibrated the existing one. What relationship does “Instead” signal?

    Impendulo

    Replacement. The second statement substitutes one action for another.

  32. Ikhadi 32

    Umbuzo

    Count nouns versus mass nouns?

    Impendulo

    Use “fewer” with countable items and “less” with amounts. Example: fewer errors, less noise.

  33. Ikhadi 33

    Umbuzo

    Effect of a counterexample?

    Impendulo

    It weakens a universal claim by showing at least one case where the claim fails.

  34. Ikhadi 34

    Umbuzo

    Rainfall was sporadic: brief showers interrupted long dry periods. Meaning of “sporadic”?

    Impendulo

    Irregular and occasional.

  35. Ikhadi 35

    Umbuzo

    The seedlings grew indoors. Subsequently, workers moved them outside. What relationship does “Subsequently” signal?

    Impendulo

    Later step in a sequence. The second event occurs after the first.

  36. Ikhadi 36

    Umbuzo

    Essential clause punctuation?

    Impendulo

    Do not surround an essential clause with commas. It identifies which person or thing the sentence means.

  37. Ikhadi 37

    Umbuzo

    Correlation alone proves causation?

    Impendulo

    No. A relationship between variables does not by itself show that one caused the other.

  38. Ikhadi 38

    Umbuzo

    Subsequent trials produced the same result. Meaning of “subsequent”?

    Impendulo

    Coming later in time.

  39. Ikhadi 39

    Umbuzo

    The coating is hydrophobic. In other words, it repels water. What relationship does “In other words” signal?

    Impendulo

    Restatement for clarity. The second statement rephrases the first.

  40. Ikhadi 40

    Umbuzo

    Verb tense across a paragraph?

    Impendulo

    Keep the time frame consistent unless the timing actually changes.

  41. Ikhadi 41

    Umbuzo

    Missing information in a data claim?

    Impendulo

    Look for the baseline, sample size, units, comparison group, or time interval needed to judge the claim.

  42. Ikhadi 42

    Umbuzo

    The coating helps the fabric retain heat. Meaning of “retain”?

    Impendulo

    Keep or continue to hold.

  43. Ikhadi 43

    Umbuzo

    The repair requires specialized tools. Specifically, it needs a torque wrench. What relationship does “Specifically” signal?

    Impendulo

    General-to-specific detail. The second statement narrows the broad first statement.

  44. Ikhadi 44

    Umbuzo

    Coordinate adjectives?

    Impendulo

    Separate them with a comma when their order can switch and “and” can fit between them. Example: “a clear, concise note.”

  45. Ikhadi 45

    Umbuzo

    Two sources on the same event?

    Impendulo

    Compare the exact claims, evidence, scope, and perspective. Shared topic does not guarantee agreement.

  46. Ikhadi 46

    Umbuzo

    The survey was designed to elicit candid responses. Meaning of “elicit”?

    Impendulo

    Draw out or bring forth.

  47. Ikhadi 47

    Umbuzo

    Heavy rain loosened the soil. Consequently, the trail closed. What relationship does “Consequently” signal?

    Impendulo

    Cause and effect. The second statement is an outcome of the first.

  48. Ikhadi 48

    Umbuzo

    Sentence fragment?

    Impendulo

    A group of words missing an independent clause. Attach it to a complete sentence or supply the missing subject and verb.

  49. Ikhadi 49

    Umbuzo

    Inference from a narrow sample?

    Impendulo

    Limit the conclusion to the population the sample can represent. Do not generalize beyond the evidence.

  50. Ikhadi 50

    Umbuzo

    Cost was the main constraint on the project. Meaning of “constraint”?

    Impendulo

    A limit or restriction.

  51. Ikhadi 51

    Umbuzo

    Early results conflicted. Ultimately, the team accepted the model. What relationship does “Ultimately” signal?

    Impendulo

    Overall conclusion. The second statement gives the final judgment after earlier considerations.

  52. Ikhadi 52

    Umbuzo

    Conjunctive adverb between independent clauses?

    Impendulo

    Use a semicolon before it and a comma after it. Example: “The route was longer; however, it was safer.”

  53. Ikhadi 53

    Umbuzo

    Most accurate summary?

    Impendulo

    State the central idea and its essential support without adding opinions or minor details.

  54. Ikhadi 54

    Umbuzo

    The review was comprehensive, covering every recorded case. Meaning of “comprehensive”?

    Impendulo

    Complete and wide-ranging.

  55. Ikhadi 55

    Umbuzo

    The method is efficient. Indeed, it cuts processing time in half. What relationship does “Indeed” signal?

    Impendulo

    Emphasis and confirmation. The second statement reinforces the first with a stronger detail.

  56. Ikhadi 56

    Umbuzo

    Who versus whom?

    Impendulo

    Use “who” as a subject and “whom” as an object. Test with he/him: “whom” matches “him.”

  57. Ikhadi 57

    Umbuzo

    Evidence that best resolves a disagreement?

    Impendulo

    Choose evidence that tests the specific point on which the sources differ, not a fact both already accept.

  58. Ikhadi 58

    Umbuzo

    The two materials have distinct properties. Meaning of “distinct”?

    Impendulo

    Clearly different or separate.

  59. Ikhadi 59

    Umbuzo

    The forecast warned of rain. Still, the outdoor concert began on time. What relationship does “Still” signal?

    Impendulo

    Concession. The second statement remains true despite the obstacle in the first.

  60. Ikhadi 60

    Umbuzo

    Comma before an introduced direct quotation?

    Impendulo

    Use a comma after a speech tag. Example: “Mina wrote, ‘The sample is ready.’”

  61. Ikhadi 61

    Umbuzo

    The conclusion was qualified by two important exceptions. Meaning of “qualified”?

    Impendulo

    Limited or modified, rather than stated without conditions.

  62. Ikhadi 62

    Umbuzo

    Notes for a synthesis goal?

    Impendulo

    Use only facts that directly serve the stated goal. Relevant notes can be omitted if they do not help that purpose.

  63. Ikhadi 63

    Umbuzo

    Comma splice?

    Impendulo

    Two independent clauses joined only by a comma. Replace it with a period or semicolon, or add a coordinating conjunction.

  64. Ikhadi 64

    Umbuzo

    Comma between subject and verb?

    Impendulo

    Do not use one unless an interrupting phrase requires paired commas. “The results of the trial were clear” takes no comma after “trial.”

  65. Ikhadi 65

    Umbuzo

    The new sensor made the older model obsolete. Meaning of “obsolete”?

    Impendulo

    No longer useful or current because something newer replaced it.

  66. Ikhadi 66

    Umbuzo

    Source attribution in a synthesis?

    Impendulo

    Name the source when its identity, authority, or perspective matters to the rhetorical goal.

  67. Ikhadi 67

    Umbuzo

    Compound subject joined by “and”?

    Impendulo

    Use a plural verb in the usual case. Example: “The map and the notes are useful.”

  68. Ikhadi 68

    Umbuzo

    Dangling opening modifier?

    Impendulo

    It lacks the intended doer immediately after the modifier. Rewrite so the doer becomes the subject.

  69. Ikhadi 69

    Umbuzo

    Researchers derived the estimate from three measurements. Meaning of “derived”?

    Impendulo

    Obtained from a source or calculation.

  70. Ikhadi 70

    Umbuzo

    Chronological synthesis?

    Impendulo

    Order events by time and use dates or sequence words only when they help the reader follow the progression.

  71. Ikhadi 71

    Umbuzo

    Plural noun ending in s: possessive form?

    Impendulo

    Add an apostrophe after the existing s. Example: “the researchers' notes.”

  72. Ikhadi 72

    Umbuzo

    Logical comparison?

    Impendulo

    Compare like with like. Example: compare one city's rainfall with another city's rainfall, not with the city itself.

  73. Ikhadi 73

    Umbuzo

    The article advocates preserving the wetland. Meaning of “advocates”?

    Impendulo

    Publicly supports or argues for.

  74. Ikhadi 74

    Umbuzo

    Compare evidence from two studies?

    Impendulo

    State the shared measure first, then the relevant difference in result, method, or population.

  75. Ikhadi 75

    Umbuzo

    Colon after an incomplete lead-in?

    Impendulo

    Do not use one. A colon must follow a complete clause, so “The reasons include:” is incorrect.

  76. Ikhadi 76

    Umbuzo

    Number versus amount?

    Impendulo

    Use “number” for countable items and “amount” for uncountable quantities. Example: number of files, amount of water.

  77. Ikhadi 77

    Umbuzo

    Portable chargers are now ubiquitous on long trips. Meaning of “ubiquitous”?

    Impendulo

    Present or found almost everywhere.

  78. Ikhadi 78

    Umbuzo

    Synthesis that emphasizes a difference?

    Impendulo

    Use the same comparison point for both subjects, then state the contrast directly.

  79. Ikhadi 79

    Umbuzo

    Nonessential clause or phrase?

    Impendulo

    Set it off with paired commas. The sentence should keep its core identity and meaning when the phrase is removed.

  80. Ikhadi 80

    Umbuzo

    Earlier of two past actions?

    Impendulo

    Use past perfect when the sequence needs clarification. Example: “The team had left before the storm began.”

  81. Ikhadi 81

    Umbuzo

    Sentence 2 presents an exception to sentence 1. Its function?

    Impendulo

    It qualifies the first claim by limiting when or how broadly it applies.

  82. Ikhadi 82

    Umbuzo

    Rhetorical goal: define a term?

    Impendulo

    Give the term's relevant meaning before using details or examples that depend on it.

  83. Ikhadi 83

    Umbuzo

    Cumulative adjectives?

    Impendulo

    Do not separate them with a comma when each adjective builds on the next. Example: “three small glass jars.”

  84. Ikhadi 84

    Umbuzo

    Run-on sentence?

    Impendulo

    Independent clauses joined without valid punctuation or a conjunction. Add a period, semicolon, or comma plus coordinating conjunction.

  85. Ikhadi 85

    Umbuzo

    Sentence 2 gives a specific case after a general claim. Its function?

    Impendulo

    It illustrates the claim with an example.

  86. Ikhadi 86

    Umbuzo

    Introduce a quotation in a synthesis?

    Impendulo

    Give enough source and context to show why the quotation matters; do not leave it unattached.

  87. Ikhadi 87

    Umbuzo

    Relative pronoun for people?

    Impendulo

    Use “who” or “whom,” depending on case. Example: “the engineer who designed the bridge.”

  88. Ikhadi 88

    Umbuzo

    Integrated quotation punctuation?

    Impendulo

    Do not add a comma when the quotation completes the grammar of the sentence. Example: The report calls the result “unexpected.”

  89. Ikhadi 89

    Umbuzo

    Sentence 2 admits a limitation before defending the claim. Its function?

    Impendulo

    It makes a concession, showing that the writer recognizes a complication.

  90. Ikhadi 90

    Umbuzo

    Avoid redundancy in synthesis?

    Impendulo

    State each needed idea once. Prefer the version that preserves meaning with fewer repeated words.

  91. Ikhadi 91

    Umbuzo

    Semicolon between two independent clauses?

    Impendulo

    Use it without a coordinating conjunction when the ideas are closely related. Example: “The trial ended; the analysis began.”

  92. Ikhadi 92

    Umbuzo

    Comma in a compound predicate?

    Impendulo

    Usually omit it when one subject performs both actions. Example: “The team collected the samples and recorded the temperature.”

  93. Ikhadi 93

    Umbuzo

    Sentence 2 explains what a technical term means. Its function?

    Impendulo

    It defines or clarifies the term.

  94. Ikhadi 94

    Umbuzo

    Combine two related sentences?

    Impendulo

    Make the logical relationship explicit and remove repeated material without changing the facts.

  95. Ikhadi 95

    Umbuzo

    Either/or subject agreement?

    Impendulo

    Make the verb agree with the nearer subject. Example: “Either the notes or the map is missing.”

  96. Ikhadi 96

    Umbuzo

    Active versus passive voice?

    Impendulo

    Choose the voice that fits the focus. Active highlights the doer; passive can highlight the action or receiver.

  97. Ikhadi 97

    Umbuzo

    Sentence 2 describes the outcome of sentence 1. Its function?

    Impendulo

    It presents an effect or consequence.

  98. Ikhadi 98

    Umbuzo

    Formal academic register?

    Impendulo

    Use precise, neutral wording and avoid slang, vague intensifiers, and chatty asides unless the goal calls for them.

  99. Ikhadi 99

    Umbuzo

    Its or it's?

    Impendulo

    “Its” is possessive; “it's” means “it is” or “it has.”

  100. Ikhadi 100

    Umbuzo

    Adjective versus adverb?

    Impendulo

    An adjective modifies a noun; an adverb usually modifies a verb, adjective, or adverb. Example: a careful test; test carefully.

  101. Ikhadi 101

    Umbuzo

    A study reports a result without arguing for a policy. Author's purpose?

    Impendulo

    To inform or explain, not necessarily to persuade.

  102. Ikhadi 102

    Umbuzo

    Concise synthesis?

    Impendulo

    Keep every fact needed for the rhetorical goal and remove details that repeat or distract from it.

  103. Ikhadi 103

    Umbuzo

    Single dash for emphasis?

    Impendulo

    Use it after a complete thought to spotlight a final explanation or turn. Example: “One result stood out—the oldest sample.”

  104. Ikhadi 104

    Umbuzo

    Comma with direct address?

    Impendulo

    Set off the person being addressed. Example: “Rina, please check the units.”

  105. Ikhadi 105

    Umbuzo

    Why acknowledge a limitation?

    Impendulo

    To define the claim's boundary and show how the evidence should be interpreted.

  106. Ikhadi 106

    Umbuzo

    Quantitative comparison in a synthesis?

    Impendulo

    Name both values, the shared unit, and the direction or size of the difference.

  107. Ikhadi 107

    Umbuzo

    Each of the samples: verb number?

    Impendulo

    Singular. “Each of the samples was labeled.” The subject is “each.”

  108. Ikhadi 108

    Umbuzo

    Between versus among?

    Impendulo

    Use “between” for distinct individual relationships and “among” for a group without separate pairings.

  109. Ikhadi 109

    Umbuzo

    Rhetorical question in an argument?

    Impendulo

    It can frame the issue or prompt the reader to consider an implied answer; it is not evidence by itself.

  110. Ikhadi 110

    Umbuzo

    Claim before or after support?

    Impendulo

    Place it where the rhetorical goal is clearest: before evidence for a direct point, or after evidence for an evidence-led conclusion.

  111. Ikhadi 111

    Umbuzo

    Restrictive “that” versus nonrestrictive “which”?

    Impendulo

    Use “that” without commas for essential information; use “which” with commas for removable information.

  112. Ikhadi 112

    Umbuzo

    Present perfect use?

    Impendulo

    Use it for an action connected to the present or continuing to now. Example: “The team has tracked rainfall since May.”

  113. Ikhadi 113

    Umbuzo

    Two texts reach the same conclusion with different evidence. Relationship?

    Impendulo

    They agree in conclusion but support it through different evidence.

  114. Ikhadi 114

    Umbuzo

    Group related ideas in a synthesis?

    Impendulo

    Keep facts serving the same point together, then signal the move to a new point.

  115. Ikhadi 115

    Umbuzo

    Compound modifier before a noun?

    Impendulo

    Hyphenate it when needed for clarity. Example: “a well-designed study.”

  116. Ikhadi 116

    Umbuzo

    Affect or effect?

    Impendulo

    “Affect” is usually a verb meaning influence; “effect” is usually a noun meaning result.

  117. Ikhadi 117

    Umbuzo

    Two texts offer incompatible explanations. Relationship?

    Impendulo

    They disagree about the cause or interpretation, even if they share the same observations.

  118. Ikhadi 118

    Umbuzo

    Replace a vague pronoun in synthesis?

    Impendulo

    Use the precise noun when two or more possible antecedents could confuse the reader.

  119. Ikhadi 119

    Umbuzo

    Comma-separated list?

    Impendulo

    Use commas between three or more parallel items. A final serial comma can prevent ambiguity.

  120. Ikhadi 120

    Umbuzo

    Main clause before a dependent clause?

    Impendulo

    Usually no comma when the dependent clause is essential. Example: “The match continued although rain fell.”

  121. Ikhadi 121

    Umbuzo

    Two authors use the same evidence but different assumptions. Key difference?

    Impendulo

    Their perspectives or interpretive frameworks, not the underlying evidence.

  122. Ikhadi 122

    Umbuzo

    Independent clauses joined with a coordinating conjunction?

    Impendulo

    Place a comma before the conjunction. Example: “The sensor failed, so the team repeated the trial.”

  123. Ikhadi 123

    Umbuzo

    Introductory transition?

    Impendulo

    Follow it with a comma when it modifies the whole sentence. Example: “However, the second trial succeeded.”

  124. Ikhadi 124

    Umbuzo

    Pronoun–antecedent agreement?

    Impendulo

    Match number and make the reference clear. Singular “they” is standard when a person's gender is unknown or irrelevant.

  125. Ikhadi 125

    Umbuzo

    Paired em dashes?

    Impendulo

    Use them to set off an emphatic interruption. Both dashes are needed when the sentence continues after it.

  126. Ikhadi 126

    Umbuzo

    How does new evidence relate to an earlier claim?

    Impendulo

    It may support, weaken, qualify, or leave the claim unchanged. Match the evidence to the exact claim.

  127. Ikhadi 127

    Umbuzo

    Their, there, or they're?

    Impendulo

    “Their” is possessive, “there” refers to place or existence, and “they're” means “they are.”

  128. Ikhadi 128

    Umbuzo

    Good or well?

    Impendulo

    “Good” is usually an adjective; “well” is usually an adverb. A person can feel good and perform well.

  129. Ikhadi 129

    Umbuzo

    Appositive naming the same noun?

    Impendulo

    Set a nonessential appositive off with commas. Example: “Dr. Rao, the lead author, presented the findings.”

  130. Ikhadi 130

    Umbuzo

    Why use an analogy?

    Impendulo

    To clarify an unfamiliar idea through a relevant similarity to something more familiar.

  131. Ikhadi 131

    Umbuzo

    Than or then?

    Impendulo

    “Than” makes a comparison; “then” refers to time or consequence.

  132. Ikhadi 132

    Umbuzo

    Hypothetical contrary-to-fact “if” clause?

    Impendulo

    Use subjunctive “were.” Example: “If the sample were larger, the estimate would be steadier.”

  133. Ikhadi 133

    Umbuzo

    Plural noun with no possession?

    Impendulo

    Do not add an apostrophe. Write “three sensors,” not “three sensor's.”

  134. Ikhadi 134

    Umbuzo

    Neutral, evidence-led wording indicates what tone?

    Impendulo

    Objective. It emphasizes information rather than strong personal judgment.

  135. Ikhadi 135

    Umbuzo

    Complex list with internal commas?

    Impendulo

    Use semicolons between the main items. Example: “Lima, Peru; Accra, Ghana; and Hanoi, Vietnam.”

  136. Ikhadi 136

    Umbuzo

    Ambiguous pronoun?

    Impendulo

    A pronoun with more than one plausible antecedent. Replace it with the intended noun.

  137. Ikhadi 137

    Umbuzo

    Parentheses around nonessential information?

    Impendulo

    Use them for an aside that is less central than the main sentence. The sentence must remain grammatical without it.

  138. Ikhadi 138

    Umbuzo

    Repeated doubt about the evidence indicates what tone?

    Impendulo

    Skeptical. The writer questions whether a claim is adequately supported.

  139. Ikhadi 139

    Umbuzo

    Superlative comparison?

    Impendulo

    Use it for one member against a group of three or more. Example: “the fastest of the four methods.”

  140. Ikhadi 140

    Umbuzo

    Pronoun after a preposition?

    Impendulo

    Use the object form. Write “between you and me,” not “between you and I.”

  141. Ikhadi 141

    Umbuzo

    Apostrophe in a contraction?

    Impendulo

    It marks omitted letters. Example: “can't” contracts “cannot,” and “they're” contracts “they are.”

  142. Ikhadi 142

    Umbuzo

    Coordinate-adjective test?

    Impendulo

    If “and” works between the adjectives and their order can reverse, use a comma between them.

  143. Ikhadi 143

    Umbuzo

    Double comparative?

    Impendulo

    Use only one comparative marker. Write “more efficient” or “faster,” not “more faster.”

  144. Ikhadi 144

    Umbuzo

    Lie or lay?

    Impendulo

    “Lie” means recline and takes no object; “lay” means place and takes an object. Present: lie/lay; past: lay/laid.

  145. Ikhadi 145

    Umbuzo

    Who's or whose?

    Impendulo

    “Who's” means “who is” or “who has”; “whose” is possessive.

  146. Ikhadi 146

    Umbuzo

    Standard comparison with “different”?

    Impendulo

    Use “different from.” Example: “This result is different from the earlier estimate.”

  147. Ikhadi 147

    Umbuzo

    Paired construction with two endpoints?

    Impendulo

    Use “between” with “and”: “between 10 and 15,” not “between 10 to 15.”

  148. Ikhadi 148

    Umbuzo

    Verb mood in a coordinated idea?

    Impendulo

    Keep the mood consistent unless the meaning changes. Do not shift from a command to a statement without reason.

  149. Ikhadi 149

    Umbuzo

    Possessive pronoun apostrophe?

    Impendulo

    Do not use one. Write “hers,” “ours,” “yours,” and “theirs.”

  150. Ikhadi 150

    Umbuzo

    Comma between a preposition and its object?

    Impendulo

    Do not use one. Keep the prepositional phrase intact: “in the final report,” not “in, the final report.”

    An open study book surrounded by punctuation marks, a coordinate graph, a right triangle, a circle, and a data chart.

    amakhadi angu-300

    Digital SAT Flashcards: Math, Grammar & Words in Context

    Funda leli qoqo mahhala

    I-Nibomo iyavuleka ukuze uqale ukufunda.

  151. Ikhadi 151

    Umbuzo

    Solve ax+b=cax+b=c for xx, where a0a≠0.

    Impendulo

    x=(cb)/ax=(c-b)/a. Subtract bb first, then divide by aa.

  152. Ikhadi 152

    Umbuzo

    Product of powers with the same base?

    Impendulo

    aman=am+na^m a^n=a^{m+n}. Keep the base and add the exponents.

  153. Ikhadi 153

    Umbuzo

    Unit rate?

    Impendulo

    The amount per 1 unit. Divide both quantities by the same value so the denominator becomes 1.

  154. Ikhadi 154

    Umbuzo

    Rectangle area?

    Impendulo

    A=lwA=lw, where ll is length and ww is width.

  155. Ikhadi 155

    Umbuzo

    Slope from two points?

    Impendulo

    m=(y2y1)/(x2x1)m=(y_2-y_1)/(x_2-x_1). Subtract coordinates in the same order.

  156. Ikhadi 156

    Umbuzo

    Quotient of powers with the same base?

    Impendulo

    am/an=amna^m/a^n=a^{m-n} for a0a≠0.

  157. Ikhadi 157

    Umbuzo

    Conversion factor setup?

    Impendulo

    Multiply by a ratio equal to 1, with the unwanted unit placed to cancel.

  158. Ikhadi 158

    Umbuzo

    Triangle area?

    Impendulo

    A=(1/2)bhA=(1/2)bh. The height must be perpendicular to the chosen base.

  159. Ikhadi 159

    Umbuzo

    Slope-intercept form?

    Impendulo

    y=mx+by=mx+b, where mm is the slope and bb is the y-intercept.

  160. Ikhadi 160

    Umbuzo

    Power raised to a power?

    Impendulo

    (am)n=amn(a^m)^n=a^{mn}. Multiply the exponents.

  161. Ikhadi 161

    Umbuzo

    Dimensional analysis check?

    Impendulo

    Cancel units algebraically. The units left at the end should match the quantity requested.

  162. Ikhadi 162

    Umbuzo

    Trapezoid area?

    Impendulo

    A=(1/2)(b1+b2)hA=(1/2)(b_1+b_2)h. The height is perpendicular to the parallel bases.

  163. Ikhadi 163

    Umbuzo

    Point-slope form?

    Impendulo

    yy1=m(xx1)y-y_1=m(x-x_1). Use a known point (x1,y1)(x_1,y_1) and the slope mm.

  164. Ikhadi 164

    Umbuzo

    Negative exponent?

    Impendulo

    an=1/ana^{-n}=1/a^n for a0a≠0.

  165. Ikhadi 165

    Umbuzo

    Constant of proportionality in y=kxy=kx?

    Impendulo

    k=y/xk=y/x for x0x≠0. It is also the unit rate and slope.

  166. Ikhadi 166

    Umbuzo

    Circle area?

    Impendulo

    A=πr2A=πr^2.

  167. Ikhadi 167

    Umbuzo

    Intercepts from Ax+By=CAx+By=C?

    Impendulo

    Set y=0y=0 for the x-intercept and set x=0x=0 for the y-intercept.

  168. Ikhadi 168

    Umbuzo

    Fractional exponent?

    Impendulo

    am/na^{m/n} means the nth root of ama^m. For example, a1/2=aa^{1/2}=√a.

  169. Ikhadi 169

    Umbuzo

    Scale drawing length?

    Impendulo

    Use a proportion with corresponding lengths in the same order, then apply the stated scale factor.

  170. Ikhadi 170

    Umbuzo

    Circle circumference?

    Impendulo

    C=2πr=πdC=2πr=πd.

  171. Ikhadi 171

    Umbuzo

    Parallel nonvertical lines: slope relationship?

    Impendulo

    They have equal slopes. Distinct parallel lines have different intercepts.

  172. Ikhadi 172

    Umbuzo

    Difference of squares?

    Impendulo

    a2b2=(ab)(a+b)a^2-b^2=(a-b)(a+b).

  173. Ikhadi 173

    Umbuzo

    Percent change?

    Impendulo

    New minus original, divided by the original, then multiplied by 100 percent. The original value is the denominator.

  174. Ikhadi 174

    Umbuzo

    Arc length from central angle θθ in degrees?

    Impendulo

    L=(θ/360)(2πr)L=(θ/360)(2πr).

  175. Ikhadi 175

    Umbuzo

    Perpendicular nonvertical lines: slope relationship?

    Impendulo

    Their slopes are negative reciprocals, so m1m2=1m_1m_2=-1.

  176. Ikhadi 176

    Umbuzo

    Perfect-square trinomial pattern?

    Impendulo

    a2+2ab+b2=(a+b)2a^2+2ab+b^2=(a+b)^2 and a22ab+b2=(ab)2a^2-2ab+b^2=(a-b)^2.

  177. Ikhadi 177

    Umbuzo

    Increase by rr percent: multiplier?

    Impendulo

    1+r/1001+r/100. Multiply the original value by this factor.

  178. Ikhadi 178

    Umbuzo

    Sector area from central angle θθ in degrees?

    Impendulo

    A=(θ/360)(πr2)A=(θ/360)(πr^2).

  179. Ikhadi 179

    Umbuzo

    x-intercept of a graph?

    Impendulo

    A point where y=0y=0 and the graph meets the x-axis.

  180. Ikhadi 180

    Umbuzo

    First step in factoring ax2+bx+cax^2+bx+c?

    Impendulo

    Look for common factors and two binomials whose product reproduces the middle and constant terms.

  181. Ikhadi 181

    Umbuzo

    Original value after a 20 percent increase to 84?

    Impendulo

    1. Divide the final value by the multiplier: $84/1.20=70$.
  182. Ikhadi 182

    Umbuzo

    Triangle interior-angle sum?

    Impendulo

    180°180°.

  183. Ikhadi 183

    Umbuzo

    y-intercept of a graph?

    Impendulo

    A point where x=0x=0 and the graph meets the y-axis.

  184. Ikhadi 184

    Umbuzo

    Roots from (xp)(xq)=0(x-p)(x-q)=0?

    Impendulo

    x=px=p or x=qx=q, by the zero-product property.

  185. Ikhadi 185

    Umbuzo

    Weighted average?

    Impendulo

    Sum of each value times its weight, divided by the sum of the weights. Do not take a simple average of unequal groups.

  186. Ikhadi 186

    Umbuzo

    Exterior angle of a triangle?

    Impendulo

    It equals the sum of the two remote interior angles.

  187. Ikhadi 187

    Umbuzo

    Line through two points?

    Impendulo

    Find the slope, then substitute either point into point-slope or slope-intercept form.

  188. Ikhadi 188

    Umbuzo

    Quadratic formula?

    Impendulo

    x=(b±(b24ac))/(2a)x=(-b±√(b^2-4ac))/(2a) for ax2+bx+c=0ax^2+bx+c=0.

  189. Ikhadi 189

    Umbuzo

    Arithmetic mean?

    Impendulo

    Add all values and divide by the number of values.

  190. Ikhadi 190

    Umbuzo

    Parallel lines cut by a transversal: alternate interior angles?

    Impendulo

    They are congruent.

  191. Ikhadi 191

    Umbuzo

    Slope's units in context?

    Impendulo

    Output units per input unit. In yy versus xx, slope units are y-units divided by x-units.

  192. Ikhadi 192

    Umbuzo

    What does b24acb^2-4ac tell you?

    Impendulo

    The number of real solutions: positive gives two, zero gives one, and negative gives none.

  193. Ikhadi 193

    Umbuzo

    Median?

    Impendulo

    The middle value after ordering the data; for an even count, average the two middle values.

  194. Ikhadi 194

    Umbuzo

    Similar triangles: corresponding sides?

    Impendulo

    They are proportional. Match sides opposite equal angles.

  195. Ikhadi 195

    Umbuzo

    Direct variation model?

    Impendulo

    y=kxy=kx. It is linear and passes through the origin.

  196. Ikhadi 196

    Umbuzo

    Vertex x-coordinate of ax2+bx+cax^2+bx+c?

    Impendulo

    x=b/(2a)x=-b/(2a).

  197. Ikhadi 197

    Umbuzo

    Range of a data set?

    Impendulo

    Maximum minus minimum.

  198. Ikhadi 198

    Umbuzo

    Scale factor kk: area factor?

    Impendulo

    k2k^2. Lengths scale by kk, while areas scale by the square of kk.

  199. Ikhadi 199

    Umbuzo

    Solution of a two-line system?

    Impendulo

    The intersection point, whose coordinates satisfy both equations.

  200. Ikhadi 200

    Umbuzo

    Vertex form of a quadratic?

    Impendulo

    y=a(xh)2+ky=a(x-h)^2+k, with vertex (h,k)(h,k).

  201. Ikhadi 201

    Umbuzo

    Interquartile range?

    Impendulo

    IQR=Q3Q1IQR=Q_3-Q_1. It measures the spread of the middle half of the data.

  202. Ikhadi 202

    Umbuzo

    Pythagorean theorem?

    Impendulo

    a2+b2=c2a^2+b^2=c^2 for a right triangle, where cc is the hypotenuse.

  203. Ikhadi 203

    Umbuzo

    Substitution in a system?

    Impendulo

    Solve one equation for a variable and replace that variable in the other equation.

  204. Ikhadi 204

    Umbuzo

    Axis of symmetry of y=a(xh)2+ky=a(x-h)^2+k?

    Impendulo

    x=hx=h.

  205. Ikhadi 205

    Umbuzo

    Larger standard deviation means what?

    Impendulo

    The data are more spread out around the mean.

  206. Ikhadi 206

    Umbuzo

    45°-45°-90° side ratio?

    Impendulo

    1:1:21:1:√2. The hypotenuse is a leg times 2√2.

  207. Ikhadi 207

    Umbuzo

    Elimination in a system?

    Impendulo

    Add or subtract equations so one variable cancels, then solve for the other.

  208. Ikhadi 208

    Umbuzo

    Completing the square?

    Impendulo

    For x2+bxx^2+bx, add (b/2)2(b/2)^2 to form (x+b/2)2(x+b/2)^2.

  209. Ikhadi 209

    Umbuzo

    Effect of a high outlier on the mean?

    Impendulo

    It usually pulls the mean upward. The median is often less affected.

  210. Ikhadi 210

    Umbuzo

    30°-60°-90° side ratio?

    Impendulo

    1:3:21:√3:2, opposite 30°30°, 60°60°, and 90°90° respectively.

  211. Ikhadi 211

    Umbuzo

    Parallel lines in a system?

    Impendulo

    No solution when they are distinct: equal slopes and different intercepts.

  212. Ikhadi 212

    Umbuzo

    Sum and product of roots of ax2+bx+c=0ax^2+bx+c=0?

    Impendulo

    Sum =b/a=-b/a and product =c/a=c/a.

  213. Ikhadi 213

    Umbuzo

    Add the same constant to every data value: effect?

    Impendulo

    The mean and median increase by that constant; measures of spread stay unchanged.

  214. Ikhadi 214

    Umbuzo

    Right-triangle sine?

    Impendulo

    Sine of θθ equals opposite over hypotenuse.

  215. Ikhadi 215

    Umbuzo

    Same line written two ways in a system?

    Impendulo

    Infinitely many solutions. Simplifying either equation produces the other.

  216. Ikhadi 216

    Umbuzo

    Remainder when P(x)P(x) is divided by xax-a?

    Impendulo

    P(a)P(a), by the Remainder Theorem.

  217. Ikhadi 217

    Umbuzo

    Multiply every data value by positive kk: effect?

    Impendulo

    The mean, median, range, IQR, and standard deviation are all multiplied by kk.

  218. Ikhadi 218

    Umbuzo

    Right-triangle cosine?

    Impendulo

    Cosine of θθ equals adjacent over hypotenuse.

  219. Ikhadi 219

    Umbuzo

    Multiply or divide an inequality by a negative number?

    Impendulo

    Reverse the inequality sign.

  220. Ikhadi 220

    Umbuzo

    When is xax-a a factor of P(x)P(x)?

    Impendulo

    When P(a)=0P(a)=0, by the Factor Theorem.

  221. Ikhadi 221

    Umbuzo

    Joint probability from a two-way table?

    Impendulo

    Divide the count in the intersection cell by the grand total.

  222. Ikhadi 222

    Umbuzo

    Right-triangle tangent?

    Impendulo

    Tangent of θθ equals opposite over adjacent.

  223. Ikhadi 223

    Umbuzo

    Compound inequality with “and”?

    Impendulo

    Use the intersection: values that satisfy both inequalities.

  224. Ikhadi 224

    Umbuzo

    Even degree with positive leading coefficient: end behavior?

    Impendulo

    Both ends rise: P(x)P(x)→∞ as x±x→±∞.

  225. Ikhadi 225

    Umbuzo

    Conditional probability P(AB)P(A|B)?

    Impendulo

    P(AB)/P(B)P(A∩B)/P(B). Restrict the denominator to outcomes in BB.

  226. Ikhadi 226

    Umbuzo

    Complementary acute angles: sine–cosine relationship?

    Impendulo

    The sine of θθ equals the cosine of 90°θ90°-θ.

  227. Ikhadi 227

    Umbuzo

    Compound inequality with “or”?

    Impendulo

    Use the union: values that satisfy at least one inequality.

  228. Ikhadi 228

    Umbuzo

    Odd degree with positive leading coefficient: end behavior?

    Impendulo

    The left end falls and the right end rises.

  229. Ikhadi 229

    Umbuzo

    Independent events AA and BB?

    Impendulo

    P(AB)=P(A)P(B)P(A∩B)=P(A)P(B). Knowing one occurred does not change the probability of the other.

  230. Ikhadi 230

    Umbuzo

    Distance between (x1,y1)(x_1,y_1) and (x2,y2)(x_2,y_2)?

    Impendulo

    ((x2x1)2+(y2y1)2)√((x_2-x_1)^2+(y_2-y_1)^2).

  231. Ikhadi 231

    Umbuzo

    Solve xa=b|x-a|=b for b0b≥0.

    Impendulo

    xa=bx-a=b or xa=bx-a=-b. Absolute value represents distance from aa.

  232. Ikhadi 232

    Umbuzo

    Exponential growth model?

    Impendulo

    y=a(1+r)ty=a(1+r)^t, where aa is the initial value and rr is the growth rate per period.

  233. Ikhadi 233

    Umbuzo

    Mutually exclusive events?

    Impendulo

    They cannot occur together, so P(AB)=P(A)+P(B)P(A∪B)=P(A)+P(B).

  234. Ikhadi 234

    Umbuzo

    Midpoint of two points?

    Impendulo

    ((x1+x2)/2,(y1+y2)/2)((x_1+x_2)/2,(y_1+y_2)/2).

  235. Ikhadi 235

    Umbuzo

    Solve xa<b|x-a|<b for b>0b>0.

    Impendulo

    ab<x<a+ba-b<x<a+b. The solution lies within distance bb of aa.

  236. Ikhadi 236

    Umbuzo

    Exponential decay model?

    Impendulo

    y=a(1r)ty=a(1-r)^t, where 0<r<10<r<1 is the decay rate per period.

  237. Ikhadi 237

    Umbuzo

    Complement rule?

    Impendulo

    The probability that AA does not occur is 1P(A)1-P(A).

  238. Ikhadi 238

    Umbuzo

    Circle with center (h,k)(h,k) and radius rr?

    Impendulo

    (xh)2+(yk)2=r2(x-h)^2+(y-k)^2=r^2.

  239. Ikhadi 239

    Umbuzo

    Evaluate f(a)f(a)?

    Impendulo

    Substitute aa for every input variable in the function rule, then simplify.

  240. Ikhadi 240

    Umbuzo

    Growth factor 1.08: percent growth rate?

    Impendulo

    8 percent. Subtract 1 and convert the decimal to a percent.

  241. Ikhadi 241

    Umbuzo

    Representative random sample permits what conclusion?

    Impendulo

    A cautious generalization from the sample to the population it represents.

  242. Ikhadi 242

    Umbuzo

    Radius from (xh)2+(yk)2=R(x-h)^2+(y-k)^2=R?

    Impendulo

    r=Rr=√R, provided R>0R>0.

  243. Ikhadi 243

    Umbuzo

    Linear table: constant slope check?

    Impendulo

    Equal changes in xx must produce equal changes in yy; compare Δy/ΔxΔy/Δx across intervals.

  244. Ikhadi 244

    Umbuzo

    Decay factor 0.73: percent decrease?

    Impendulo

    27 percent. Compute 10.73=0.271-0.73=0.27.

  245. Ikhadi 245

    Umbuzo

    Random assignment permits what causal claim?

    Impendulo

    If the experiment is well controlled, differences between treatment groups can support a causal conclusion.

  246. Ikhadi 246

    Umbuzo

    Radius and tangent at the contact point?

    Impendulo

    They are perpendicular.

  247. Ikhadi 247

    Umbuzo

    Positive slope means what for a linear function?

    Impendulo

    The output increases as the input increases.

  248. Ikhadi 248

    Umbuzo

    Solve 32x=3103^{2x}=3^{10}.

    Impendulo

    x=5x=5. Equal positive bases other than 1 have equal exponents.

  249. Ikhadi 249

    Umbuzo

    Observational study supports causation?

    Impendulo

    No. It can show association, but uncontrolled confounding variables may explain the pattern.

  250. Ikhadi 250

    Umbuzo

    Rectangular-prism volume?

    Impendulo

    V=lwhV=lwh, or base area times height.

  251. Ikhadi 251

    Umbuzo

    Arithmetic sequence common difference?

    Impendulo

    Subtract consecutive terms: d=anan1d=a_n-a_{n-1}.

  252. Ikhadi 252

    Umbuzo

    Compound interest formula?

    Impendulo

    A=P(1+r/n)ntA=P(1+r/n)^{nt}, where nn is the number of compounding periods per year.

  253. Ikhadi 253

    Umbuzo

    Larger random sample: effect on margin of error?

    Impendulo

    It generally decreases the margin of error when the sampling method stays sound.

  254. Ikhadi 254

    Umbuzo

    Cylinder volume?

    Impendulo

    V=πr2hV=πr^2h.

  255. Ikhadi 255

    Umbuzo

    Arithmetic sequence nth term?

    Impendulo

    an=a1+(n1)da_n=a_1+(n-1)d.

  256. Ikhadi 256

    Umbuzo

    Rational expression: first domain check?

    Impendulo

    Exclude values that make any original denominator zero, even if a factor later cancels.

  257. Ikhadi 257

    Umbuzo

    Slope of a line of best fit?

    Impendulo

    The predicted change in the response variable for each 1-unit increase in the explanatory variable.

  258. Ikhadi 258

    Umbuzo

    Cone volume?

    Impendulo

    V=(1/3)πr2hV=(1/3)πr^2h.

  259. Ikhadi 259

    Umbuzo

    Solve a literal equation for one variable?

    Impendulo

    Treat the other symbols as constants and use inverse operations to isolate the target variable.

  260. Ikhadi 260

    Umbuzo

    Why check rational-equation solutions?

    Impendulo

    Clearing denominators can produce a value excluded from the original equation. Reject any value that makes an original denominator zero.

  261. Ikhadi 261

    Umbuzo

    Residual?

    Impendulo

    Actual value minus predicted value. A positive residual means the point lies above the model.

  262. Ikhadi 262

    Umbuzo

    Sphere volume?

    Impendulo

    V=(4/3)πr3V=(4/3)πr^3.

  263. Ikhadi 263

    Umbuzo

    Boundary for a two-variable linear inequality?

    Impendulo

    Replace the inequality with equality to draw the boundary line, then test a point for the shaded side.

  264. Ikhadi 264

    Umbuzo

    Why check a solution after squaring both sides?

    Impendulo

    Squaring can introduce an extraneous solution. Substitute each candidate into the original radical equation.

  265. Ikhadi 265

    Umbuzo

    Positive correlation?

    Impendulo

    Larger values of one variable tend to occur with larger values of the other. It does not prove causation.

  266. Ikhadi 266

    Umbuzo

    Rectangular-prism surface area?

    Impendulo

    SA=2(lw+lh+wh)SA=2(lw+lh+wh).

  267. Ikhadi 267

    Umbuzo

    Check a proposed system solution?

    Impendulo

    Substitute the ordered pair into both original equations. It must make both true.

  268. Ikhadi 268

    Umbuzo

    Simplify 72√72.

    Impendulo

    626√2. Factor 72=36×272=36×2 and take 36√36 outside the radical.

  269. Ikhadi 269

    Umbuzo

    Extrapolation risk?

    Impendulo

    A model may not keep the same pattern outside the observed data range.

  270. Ikhadi 270

    Umbuzo

    Area scale factor when lengths double?

    Impendulo

    1. Area scales with the square of the length factor: $2^2=4$.
  271. Ikhadi 271

    Umbuzo

    Horizontal line slope?

    Impendulo

    1. Its y-value does not change as x changes.
  272. Ikhadi 272

    Umbuzo

    Inverse function setup?

    Impendulo

    Write y=f(x)y=f(x), swap xx and yy, then solve for yy. Restrict the domain when needed to make the inverse a function.

  273. Ikhadi 273

    Umbuzo

    Percentage points versus percent change?

    Impendulo

    A rate moving from 40 percent to 50 percent rises 10 percentage points but 25 percent relative to 40.

  274. Ikhadi 274

    Umbuzo

    y-intercept in a context?

    Impendulo

    The predicted or initial output when the input is zero; check whether zero is meaningful in the situation.

  275. Ikhadi 275

    Umbuzo

    Quadratic maximum or minimum from vertex form?

    Impendulo

    The vertex value is kk in a(xh)2+ka(x-h)^2+k; it is a minimum if a>0a>0 and a maximum if a<0a<0.

  276. Ikhadi 276

    Umbuzo

    Line parallel to y=mx+by=mx+b through (p,q)(p,q)?

    Impendulo

    yq=m(xp)y-q=m(x-p). Parallel lines keep the same slope.

  277. Ikhadi 277

    Umbuzo

    Graph of f(xh)+kf(x-h)+k?

    Impendulo

    Shift the graph of ff right hh units and up kk units.

  278. Ikhadi 278

    Umbuzo

    Population versus sample?

    Impendulo

    The population is the full group of interest; a sample is the subset actually observed.

  279. Ikhadi 279

    Umbuzo

    Linear model from initial value bb and rate mm?

    Impendulo

    y=mx+by=mx+b. The initial value is the output at input zero.

  280. Ikhadi 280

    Umbuzo

    Function composition (fg)(x)(f∘g)(x)?

    Impendulo

    f(g(x))f(g(x)). Evaluate the inner function gg first.

  281. Ikhadi 281

    Umbuzo

    Density?

    Impendulo

    Mass divided by volume. Keep the units consistent.

  282. Ikhadi 282

    Umbuzo

    Vertical line slope?

    Impendulo

    Undefined because Δx=0Δx=0, which would require division by zero.

  283. Ikhadi 283

    Umbuzo

    Nonlinear system with one equation solved for yy?

    Impendulo

    Substitute that expression for yy into the other equation, solve for xx, then find each matching yy.

  284. Ikhadi 284

    Umbuzo

    Weighted percentage across unequal groups?

    Impendulo

    Convert each percentage to a count or weight, add the successes, then divide by the combined total.

  285. Ikhadi 285

    Umbuzo

    Line perpendicular to a nonzero finite slope mm through (p,q)(p,q)?

    Impendulo

    Use slope 1/m-1/m in yq=(1/m)(xp)y-q=(-1/m)(x-p), when mm is nonzero and finite.

  286. Ikhadi 286

    Umbuzo

    Cancel a common factor in a rational expression?

    Impendulo

    Cancel factors, not terms, and keep every restriction from the original denominator.

  287. Ikhadi 287

    Umbuzo

    Solve a linear equation containing fractions?

    Impendulo

    Multiply every term by the least common denominator first, then solve the resulting linear equation.

  288. Ikhadi 288

    Umbuzo

    Rewrite a2xa^{2x} using base axa^x.

    Impendulo

    (ax)2(a^x)^2. This can turn an exponential expression into a quadratic form.

  289. Ikhadi 289

    Umbuzo

    Rate units check?

    Impendulo

    Write the numerator and denominator units explicitly, such as kilometers per hour, then convert only if the requested units differ.

  290. Ikhadi 290

    Umbuzo

    Strict versus inclusive inequality endpoint?

    Impendulo

    Use an open point for << or >> and a closed point for or .

  291. Ikhadi 291

    Umbuzo

    Even-multiplicity zero on a graph?

    Impendulo

    The graph touches the x-axis and turns around; it does not cross there.

  292. Ikhadi 292

    Umbuzo

    System word problem: first setup step?

    Impendulo

    Define the variables with units, then translate two independent relationships into equations.

  293. Ikhadi 293

    Umbuzo

    When does a quadratic have exactly one real solution?

    Impendulo

    When b24ac=0b^2-4ac=0. The repeated root is the vertex's x-coordinate.

  294. Ikhadi 294

    Umbuzo

    Two-way table: denominator for “among group B”?

    Impendulo

    Use the total for group B, not the grand total. The wording makes B the condition.

  295. Ikhadi 295

    Umbuzo

    Find an input when f(x)=kf(x)=k.

    Impendulo

    Set the function rule equal to kk and solve for xx; there may be zero, one, or several inputs.

  296. Ikhadi 296

    Umbuzo

    Graph of f(x)-f(x)?

    Impendulo

    Reflect the graph of f(x)f(x) across the x-axis.

  297. Ikhadi 297

    Umbuzo

    Three consecutive integers starting with nn?

    Impendulo

    nn, n+1n+1, and n+2n+2.

  298. Ikhadi 298

    Umbuzo

    Line–parabola intersections from a substituted quadratic?

    Impendulo

    Use its discriminant: positive means two intersections, zero one tangent intersection, and negative none.

  299. Ikhadi 299

    Umbuzo

    Linear equation with no solution: coefficient pattern?

    Impendulo

    After simplification, the variable terms cancel and leave a false statement, such as 0=50=5.

  300. Ikhadi 300

    Umbuzo

    Zeros of a function on its graph?

    Impendulo

    The x-coordinates where the graph meets the x-axis, so f(x)=0f(x)=0.

An open study book surrounded by punctuation marks, a coordinate graph, a right triangle, a circle, and a data chart.

amakhadi angu-300

Digital SAT Flashcards: Math, Grammar & Words in Context

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