Advanced Math practice question

Answer: 7

Square both sides: 2x + 2 = x² − 6x + 9, so x² − 8x + 7 = (x − 1)(x − 7) = 0. Check x = 1: √4 = 2 but 1 − 3 = −2 — rejected. Check x = 7: √16 = 4 = 7 − 3 ✓. So x = 7.

Common wrong answers

If you answered 1

1 is the extraneous root: it makes the right side −2, but a square root is never negative.

If you answered 3

3 makes the right side 0 but the left side √8.

If you answered -1

−1 makes the radicand 0 and the right side −4; not a solution.

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