Hello, how do I simplify powers that are inside roots? Example: say x is a positive number (I don't know how to write the math on a PC sorry)

sq< 9x^8

[Square root of nine and x to the power of 8]

To simplify, I can square root 9 to get 3, and take that to the outside of the root.

3 sq< x^8

But what about the x to the power of 8? I have no idea