Answer
$\dfrac{a^{2}}{bc^{3}}$
Work Step by Step
Using the laws of exponents, the given expression, $
(a^{-2}bc^3)^{-1}
$, is equivalent to
\begin{array}{l}\require{cancel}
a^{-2(-1)}b^{-1}c^{3(-1)}
\\\\=
a^{2}b^{-1}c^{-3}
\\\\=
\dfrac{a^{2}}{b^{1}c^{3}}
\\\\=
\dfrac{a^{2}}{bc^{3}}
.\end{array}