Answer
$\frac{x^2}{8 z^7}$
Work Step by Step
We start with the given expression: $2^{-3}x^2z^{-7}$
The negative exponent rule states that for every nonzero number $a$ and integer $n$, $a^{-n}=\frac{1}{a^n}$.
We use this rule to rearrange the expression as follows: $\frac{x^2}{2^3z^7}$
We expand the constant exponent in the denominator: $\frac{x^2}{2\times2\times2\times z^7}=\frac{x^2}{8 z^7}$