Answer
$-3a^{4}$
Work Step by Step
$\bf{\text{Solution Outline:}}$
Use the properties of radicals to simplify the given expression, $
\sqrt[3]{-27a^{12}}
.$
$\bf{\text{Solution Details:}}$
Using the properties of radicals, the expression above simplifies to
\begin{array}{l}\require{cancel}
\sqrt[3]{-27a^{12}}
\\\\=
\sqrt[3]{(-3a^{4})^3}
\\\\=
-3a^{4}
.\end{array}