The square root of ((10 + √25)(12 – √49)) is:
2025
The square root of ((10 + √25)(12 – √49)) is:
- A.
4√3
- B.
3√3
- C.
5√3
- D.
2√3
Attempted by 6 students.
Show answer & explanation
Correct answer: C
Concept: To simplify the square root of a product like √[(a)(b)], first evaluate any perfect-square roots inside each factor, then multiply the simplified factors, and finally extract the largest perfect-square factor from the result using the identity √(m²·n) = m√n.
Applying it here:
Evaluate the inner square roots: √25 = 5 and √49 = 7.
Substitute back into each factor: (10 + 5) = 15 and (12 − 7) = 5.
Multiply the two simplified factors: 15 × 5 = 75.
Factor 75 to isolate the largest perfect square: 75 = 25 × 3.
Apply √(m²·n) = m√n: √75 = √(25 × 3) = 5√3.
Cross-check: Squaring 5√3 gives 25 × 3 = 75, which matches the product computed above, confirming the simplification.