## Intermediate Algebra (12th Edition)

$-\frac{1}{a^{3}}$
According to the negative exponent rule, $a^{-n}=\frac{1}{a^{n}}$. Therefore, $-a^{-3}=\frac{-1}{a^{3}}=-\frac{1}{a^{3}}$. Recall that the base of the exponent is $a$ and not $-a$.