Answer
$\dfrac{1}{64}$
Work Step by Step
Using $a^{-x}=\dfrac{1}{a^x}$ or $\dfrac{1}{a^{-x}}=a^x$ and the laws of exponents, the given expression, $
4^{-3}
,$ is equivalent to
\begin{array}{l}\require{cancel}
\dfrac{1}{4^3}
\\\\=
\dfrac{1}{64}
.\end{array}