Advanced Math practice question

Answer: A. 5√2

Factor out the largest perfect square: 50 = 25 × 2. Then √50 = √25 · √2 = 5√2. (Check: (5√2)² = 25 × 2 = 50.)

Why the other answers are wrong

B. 25√2

√25 is 5, not 25. Taking the root of the perfect-square factor is what brings it outside the radical.

C. 2√5

The perfect square inside 50 is 25, so 5 comes out and 2 stays in, not the other way round. (2√5)² = 20, not 50.

D. 10√5

(10√5)² = 100 × 5 = 500, ten times too big. 50 doesn't contain a factor of 100.

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