#### Answer

$-7y$

#### Work Step by Step

Using the properties of radicals, the given expression, $
-\sqrt[3]{(7y)^3}
,$ simplifies to
\begin{array}{l}
-(7y)
\\\\=
-7y
.\end{array}
Note that it is assumed that no radicand was formed by raising negative quantities to even powers. Thus, absolute value bars are not necessary.