Hi! Can someone check this and see if they are correct? Thanks!

Question

1.) Which value of x should the expression be further simplified? √(21)x

a.) 5
B.) 6
c.) 11
D. 55

My answer: a

2.) 2√43x is show: Which value of x makes the expression equivalent to 14√43?

a.) 7
b.) 12
c.) 49
d.) 98

My answer: a

3.) Which value of x should the expression be further simplified? √(55)x

a.) 7
b.) 12
c.) 13
d.) 15

My answer: d

Answer 1

2. 2*Sqrt(43x) = 14*Sqrt(43)
Square both sides:
4*43x = 196*43
4x = 196
X = 49

Answer 2

For what value of X can the expression Square root of 55X be further simplified?