8

Set 14: Linear Inequalities (Intermediate)

Explanation

Answer: A

Solve: 7x43x+127x - 4 \geq 3x + 12

A.

x4x \geq 4

✓ Correct
B.

x4x \leq 4

C.

x2x \geq 2

D.

x2x \leq 2

Detailed Explanation

Choice A is correct. Choice A is the correct answer. Variables on both sides require systematic isolation. 1. Subtract 3 x: 7x3x43x3x+127x - 3 x - 4 \geq 3 x - 3 x + 12, giving 4x4124x - 4 \geq 12 2. Add 4: 4x4+412+44x - 4 + 4 \geq 12 + 4, giving 4x164x \geq 16 3. Divide by 4: x4x \geq 4 Strategic Tip: Move all variable terms to one side before working with constants to avoid confusion. Choice B is incorrect because it reverses the inequality without mathematical reason. Choice C is incorrect because it might result from incorrect arithmetic, perhaps dividing 8 by 4 instead of 16. Choice D is incorrect because it combines both wrong value and wrong direction.

Key Steps:

The correct answer is x4x \geq 4

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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