7

Set 8: Linear Inequalities

Explanation

Answer: A

A gym charges a $50initiation fee and \30 per month. A competitor charges no initiation fee but $40 per month. After how many months $$m$ is the competitor's gym more expensive?

A.

m>5m > 5

✓ Correct
B.

m<5m < 5

C.

m>2m > 2

D.

m<2m < 2

Detailed Explanation

Choice A is correct. Choice A is the correct answer. Compare the total costs of both gyms. 1. Gym 1 Cost: 50+30m50+ 30 m 2. Gym 2 Cost: 40m40m 3. Condition: Gym 2 > Gym 1 4. Inequality: 40m>50+30m40m > 50 + 30 m 5. Subtract 30 m: 10m>5010m > 50 6. Divide by 10: m>5m > 5 Strategic Tip: Set up an expression for each option and use the inequality symbol that matches the question ("more expensive" = >>). Choice B is incorrect because it reverses the direction (m<5m < 5), implying the competitor is cheaper after 5 months. Choice C is incorrect because it uses the wrong value. Choice D is incorrect because it combines wrong value and wrong direction.

Key Steps:

The correct answer is m>5m > 5

Why others are wrong:
B: Choice B is incorrect and may result from a calculation error.
C: Choice C is incorrect and may result from a calculation error.
D: Choice D is incorrect and may result from a calculation error.

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