Answer
$\displaystyle \frac{1}{2x^{6}y^{2}z}$
Work Step by Step
We simplify:
$\displaystyle \frac{4x^{-2}(yz)^{-1}}{2^{3}x^{4}y}=
\frac{4x^{-2}y^{-1}z^{-1}}{8x^{4}y^1}
=\frac{4}{8}x^{-2-4}y^{-1-1}z^{-1}
=\frac{1}{2}x^{-6}y^{-2}z^{-1}
=\frac{1}{2x^{6}y^{2}z}$
