What's a rule that could be used to simply the square of any square root of a number?

Step-by-step explanation:

The squaring function x^2 and the square root function √x are inverses of one another. Because of this, the square of the square root of a number is the number itself: [√x]^2; this is identical to √[ x^ (1/2) ]^2 = x^ (2/2) = x^1.

If we are given the square root of a number, then the number itself is the square of the given square root.

Example: Given x with the info that x is the square root of a number, then the square of that x is x^2.