Can someone explain to me how to use square root? How do I solve it? How do I use it? I'm not sure the right way to use square root and I have testing soon, so I wanted to know how to use it beforehand.

 a square root of a number x is a number y such that y² = x; in other words, a number y whose square is x. For example, 4 and −4 are square roots of 16, because 4² = ² = 16

The square of any number is always a positive number, so every number has two square roots, one of a positive value, and one of a negative value. For example, both 2 and -2 are square roots of 4.