Answer
$w=\{ 0,-7 \}$
Work Step by Step
By the Zero-Product Property, $ab=0$ implies $a=0 \text{ OR } b=0$. Hence, the solution to the given equation, $
w(w+7)=0
$, is
\begin{array}{}
w=0
,\\\\\text{OR}\\\\
w+7=0
\\
w=0-7
\\
w=-7
.\end{array}
Hence, $
w=\{ 0,-7 \}
$.
