Answer
$x=-7$.
Work Step by Step
The given equation is
$\Rightarrow (x+7)^2=0$
Take the square root of each side.
$\Rightarrow x+7=0$
Subtract $7$ from each side.
$\Rightarrow x+7-7=0-7$
Simplify.
$\Rightarrow x=-7$
Hence, the only solution is $x=-7$.
