Advanced Math practice question

Answer: A. 7 and −7

Two numbers square to 49: 7² = 49 and (−7)² = 49. Taking a square root to solve an equation gives both the positive and the negative root.

Why the other answers are wrong

B. 7 only

7 is a solution, but so is −7, since (−7)² = 49 as well. Solving x² = k always yields two solutions when k is positive.

C. 49 and −49

49 and −49 are the numbers whose squares are 2401, not 49. The solutions are the square roots of 49, which are ±7.

D. 24.5 and −24.5

Halving 49 isn't undoing a square. To undo x², take the square root, not half.

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