Answer
The solution is $x=-4$.
Work Step by Step
The given equation is
$-8x-16=x^2$
Add $8x+16$ to each side.
$-8x-16+8x+16=x^2+8x+16$
Simplify.
$0=x^2+8x+16$
Graph the related function.
$f(x)=x^2+8x+16$
The $x-$intercept is $-4$.
Hence, the solution is $x=-4$.
