Set 15: Linear Inequalities

Choice A is correct. Choice A is the correct answer. Area = Length $\times$ Width. 1. Area Formula: $4(x + 5)$ 2. Constraint: At least 40 $\rightarrow \geq 40$ 3. Inequality: $4(x + 5) \geq 40$ 4. Divide by 4: $x + 5 \geq 10$ 5. Subtract 5: $x \geq 5$ Strategic Tip: You can also distribute first: $4x + 20 \geq 40 \rightarrow 4 x \geq 20 \rightarrow x \geq 5$. Choice B is incorrect because it reverses the inequality direction. Choice C is incorrect because it forgets to subtract 5. Choice D is incorrect because it subtracts 5 from 40 directly without dividing by 4.