Answer
$$ x=3$$
Work Step by Step
Re-write the given equation as: $(\dfrac{1}{4})^{x}=(\dfrac{1}{4})^3$
or, $4^{-x} =4^{-3}$
Use the rule power rule: $a^p=a^q$ .
We can see that the base $a=4$ is the same on both sides of the equation.
So, the exponents will also be equal.
This implies that $p=q$
Therefore, $ -x=-3 \implies x=3$