Answer
$\color{blue}{\left\{-2, 2\right\}}$
Work Step by Step
Add $4$ to both sides:
$$(p+5)^2=4$$
Take the square root of both sides:
\begin{align*}
\sqrt{(p+5)^2}&=\pm\sqrt{4}\\
p+5&=\pm2\\
\end{align*}
Subtract $5$ from each side:
\begin{align*}
p&=-5\pm2\\
p_1&=-5-2=-7\\
p_2&=-5+2=-3
\end{align*}
Therefore, the solution set is $\color{blue}{\left\{-2, 2\right\}}$.