#### Answer

$\text{$y-$intercept: }
0$

#### Work Step by Step

Setting $x=0$ and then solving for $y$, then the $y-$intercept of the given equation, $
y=x^2+8x
,$ is
\begin{array}{l}\require{cancel}
y=(0)^2+8(0)
\\\\
y=0+0
\\\\
y=0
.\end{array}
Hence, the $y-$intercept is
\begin{array}{l}\require{cancel}
\text{$y-$intercept: }
0
.\end{array}