Answer
$x=3$
Work Step by Step
We are given that $4^{x}=64$. Both of these numbers are powers of 4, so we can rewrite the equation as $4^{x}=4^{3}$.
From the uniqueness of $b^{x}$, we know that $b^{x}=b^{y}$ is equivalent to $x=y$ (when $b\gt0$ and $b\ne1$).
Therefore, $x=3$.
