Answer
$p=-1\pm\sqrt{5}$
Work Step by Step
Using the completing the square method, the values of $p$ that satisfy the equation $
p^2+2p=4
$ are
\begin{array}{l}
p^2+2p+\left( \dfrac{2}{2} \right)^2=4+\left( \dfrac{2}{2} \right)^2
\\\\
p^2+2p+1=4+1
\\\\
(p+1)^2=5
\\\\
p+1=\pm\sqrt{5}
\\\\
p=-1\pm\sqrt{5}
\end{array}
