Answer
$\dfrac{64}{{y^{2}}}$
Work Step by Step
Using laws of exponents, the expression $
\left(\dfrac{2^{-3}}{y}\right)^{-2}
$ simplifies to
\begin{array}{l}
2^{-3(-2)}{y^{-2}}
\\\\=
2^{6}{y^{-2}}
\\\\=
\dfrac{2^{6}}{{y^{2}}}
\\\\=
\dfrac{64}{{y^{2}}}
.\end{array}
