Answer
$\frac{6a^{4}}{b^{12}}$
Work Step by Step
We are given the expression $\frac{18ab^{-6}}{3a^{-3}b^{6}}$. We can use the quotient rule to simplify.
$\frac{18ab^{-6}}{3a^{-3}b^{6}}=\frac{18}{3}\times(a^{1-(-3)})\times(b^{-6-6})=6a^{4}b^{-12}$
We know that $a^{-n}=\frac{1}{a^{n}}$, so this expression further simplifies to $\frac{6a^{4}}{b^{12}}$.