simplify the the lowest term

Question

1. square root of 40x^3

2. square root of 3/4 times square root of 4/7

3. square root of 6 + square root of 20

Answer 1

√(40x^3) = √(4x^2)√(10x) = 2x√(10x)
√(3/4) * √(4/7) = √(3*4 / 4*7) = √(3/7)
√6 + √20 = √6 + 2√5