Set 10: Linear Inequalities

Choice A is correct. Choice A is the correct answer. This real-world problem requires setting up and solving an inequality. 1. Set up: Total score is $42+ s$, need "at least 85" means $42+ s \geq 85$ 2. Solve: Subtract 42: $s \geq 85 - 42$ 3. Calculate: $s \geq 43$ Strategic Tip: "At least" translates to $\geq$ (greater than or equal to), indicating a minimum threshold. Choice B is incorrect because $\leq 43$ would represent a maximum score, not a minimum. Choice C is incorrect because it adds 42 and 85 instead of subtracting, misunderstanding the operation needed. Choice D is incorrect because while this setup is partially correct in form, it uses $\leq$ instead of $\geq$, contradicting "at least".