Answer
Solution set = $\{-6,-1\}$
Work Step by Step
Use the square root property:
If $u^{2}=d$ then $u=\pm\sqrt{d}$
Here, $u=2x+7, \quad d=25,\quad\sqrt{d}=5$
Apply the property
$2x+7=\pm 5 \quad$ ... add $-7$ to both sides
$ 2x=-7\pm 5\quad$ ... divide with $2$
$x=\displaystyle \frac{-7\pm 5}{2}\Rightarrow\left\{\begin{array}{l}
x=\frac{-7-5}{2}=-6,\\
\\
x=\frac{-7+5}{2}=-1
\end{array}\right.$
Solution set = $\{-6,-1\}$
