When rewriting inequalities it's important to make the the same operation on both sides to ensure that the inequality still holds. If one side is raised to a power, the same operation must be performed on the other side. In the inequality x≤8, both sides can be raised to the power of 2.
(x)2≤82
However, this operation should only be used when the bases on both sides are positive. Otherwise, we need to divide the inequality into cases and check absolute values.