1.
Use this rule: √ab = √a√b
√x^36√y^64
Simplify √x^36 to x^18
x^18√y^64
Simplify √y^64 to y^32
Answer: C. x^18y^32
2.
Use this rule:√ab = √a√b
√28√x^4
Simplify √28 to 2√7
2√7√x^4
Simplify √x^4 to x^2
Answer: B. 2x^2√7
3.
Rationalize the denominator: 5/√5(√5/√5) = 5√5/5
5√5/5
Cancel 5
Answer: B. √5