7

Set 13: Quadratic Equations

Explanation

Answer: A

Solve for xx: 2x+3=x\sqrt{2x + 3} = x.

A.

3

✓ Correct
B.

3, -1

C.

-1

D.

No solution

Detailed Explanation

Choice A is correct. Choice A is the correct answer. 1. Square both sides: 2x+3=x22x + 3 = x^2. 2. Rearrange: x22x3=0x^2 - 2 x - 3 = 0. 3. Factor: (x3)(x+1)=0(x - 3)(x + 1) = 0. 4. Potential roots: 3,13, -1. 5. Check: 2(3)+3=9=3\sqrt{2(3)+3} = \sqrt{9} = 3 (Matches x). 2(1)+3=1=11\sqrt{2(-1)+3} = \sqrt{1} = 1 \neq -1. So -1 is extraneous. Choice B is incorrect because -1 is extraneous. Choice C is incorrect. Choice D is incorrect.

Key Steps:

The correct answer is 3

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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