To raise a number to a power means to multiply, using the number as a factor as many times as the power indicates.
Many formulas require the power or roots of a number.
When an exponent occurs, it must always be written unless its value is 1. This example is what we call the root of a perfect square. As you can see, we were able to extract only the square root of 9, and 3 remains in the radical because it is an irrational factor. This simplification of the radical makes the solution easier because you will be dealing with perfect squares and smaller numbers. Radicals are multiplied or divided directly.