5

Set 14: Linear Inequalities

Explanation

Answer: A

A bakery makes bread (xx) and cakes (yy). It takes 1 hour to make bread and 2 hours to make a cake. They have at most 10 hours available. They want to make at least 2 loaves of bread. Which system models this?

A.

x+2y10x + 2y \leq 10 and x2x \geq 2

✓ Correct
B.

x+2y10x + 2y \geq 10 and x2x \geq 2

C.

2x+y102x + y \leq 10 and x2x \geq 2

D.

x+2y10x + 2y \leq 10 and y2y \geq 2

Detailed Explanation

Choice A is correct. Choice A is the correct answer. Translate constraints into inequalities. 1. Time Constraint: 1x1x (bread) + 2y2y (cake) 10\leq 10 (hours). x+2y10\rightarrow x + 2 y \leq 10 2. Quantity Constraint: Bread (xx) at least 2. x2\rightarrow x \geq 2 3. System: x+2y10x + 2 y \leq 10 and x2x \geq 2 Strategic Tip: Match the coefficients to the correct variables (1 hour for bread, 2 for cake). Choice B is incorrect because 10\geq 10 means they must work more than 10 hours. Choice C is incorrect because it swaps the time coefficients. Choice D is incorrect because it puts the quantity constraint on cakes (yy) instead of bread.

Key Steps:

The correct answer is x+2y10x + 2y \leq 10 and x2x \geq 2

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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