A student needs at least 90 points to get an A. She scored 87 on her first test. Let \(s\) = her second test score needed (average of 2 tests). Which models the requirement?
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Memory Key: Average = sum ÷ count Average of 2 tests: \(\frac{87 + s}{2} \geq 90\)
A \(87 + s \geq 90\)
B \(\dfrac{87 + s}{2} \geq 90\)
C \(\dfrac{87 + s}{2} > 90\)
D \(s \geq 90\)
Part 3 — Solving One-Step Inequalities
11
SolvingAdd/Subtract
Solve: \(x + 7 < 3\)
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Memory Key: Add/Subtract → sign stays same Subtract 7 from both sides. The inequality direction does NOT flip.
A \(x < 10\)
B \(x > -4\)
C \(x < -4\)
D \(x \leq -4\)
12
SolvingFlip the Sign!
Solve: \(-3x \geq 12\)
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🔥 Memory Key: FLIP when dividing/multiplying by NEGATIVE! Divide both sides by −3 → inequality flips from ≥ to ≤. This is the #1 most common mistake!
A \(x \geq -4\)
B \(x \leq 4\)
C \(x \geq 4\)
D \(x \leq -4\)
13
SolvingDivide
Solve: \(\dfrac{x}{5} \leq -2\)
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Memory Key: Multiply by POSITIVE → no flip Multiply both sides by 5 (positive). Sign stays ≤.
A \(x \leq -7\)
B \(x \leq -10\)
C \(x \geq -10\)
D \(x \leq 10\)
14
SolvingNegative Multiply
Solve: \(-\dfrac{x}{4} > 3\)
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🔥 Memory Key: FLIP when multiplying by −4 Multiply both sides by −4 → flip > to <. Result: \(x < -12\).
A \(x < -12\)
B \(x > -12\)
C \(x > 12\)
D \(x < 12\)
15
SolvingTwo-Step
Solve: \(2x + 3 > 11\)
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Memory Key: Two-step → undo addition FIRST, then division Step 1: subtract 3 → \(2x > 8\). Step 2: divide by 2 (positive, no flip) → \(x > 4\).
A \(x > 7\)
B \(x > 4\)
C \(x \geq 4\)
D \(x < 4\)
Part 4 — Number Line Interpretation
16
GraphOpen/Closed
A number line shows a closed circle at 3, shading to the right. Which inequality does this represent?
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Memory Key: Open = strict (< or >), Closed = equal included (≤ or ≥) Closed dot = the number IS included = ≥ or ≤.
A \(x > 3\)
B \(x \geq 3\)
C \(x \leq 3\)
D \(x < 3\)
17
GraphTricky
Which value is NOT a solution of \(x \leq -2\)?
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Memory Key: Substitute to test! Plug each option into \(x \leq -2\). If the statement is FALSE, that's your answer.
A \(-5\)
B \(-2\)
C \(-10\)
D \(0\)
18
GraphHard
After solving \(5 - 2x > 9\), you graph the solution on a number line. Which description is correct?
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🔥 Remember: Solve first, FLIP when dividing by negative! \(5 - 2x > 9\) → \(-2x > 4\) → divide by −2, flip → \(x < -2\). Open circle at −2, shade LEFT.
A Open circle at \(-2\), shading to the right
B Closed circle at \(-2\), shading to the left
C Open circle at \(-2\), shading to the left
D Open circle at \(2\), shading to the left
Part 5 — Challenge & Mixed Problems
19
ChallengeWord Problem
A taxi charges a flat fee of $3 plus $2 per mile. Jenna has at most $15 to spend. What is the maximum number of miles she can ride? Set up the inequality.
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Memory Key: flat fee + rate × miles ≤ budget \(3 + 2m \leq 15\) → \(2m \leq 12\) → \(m \leq 6\). She can ride at most 6 miles.
A \(2m \leq 15\), so \(m \leq 7.5\)
B \(3 + 2m \leq 15\), so \(m \leq 6\)
C \(3 + 2m < 15\), so \(m < 6\)
D \(3m + 2 \leq 15\), so \(m \leq \frac{13}{3}\)
20
ChallengeBoss Level
Which of the following inequalities has the solution \(x > -3\)?
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Memory Key: Work backwards — substitute \(x = -3\) as boundary test Try \(x = 0\) (should work) and \(x = -5\) (should NOT work) in each option to verify.