$$y= { x }^{ 2 } +2x-8$$
$x=\sqrt{y+9}-1$
$x=-\sqrt{y+9}-1$
$x=\sqrt{y+9}-1$
$x=-\sqrt{y+9}-1\text{, }y\geq -9$
$y=\left(x-2\right)\left(x+4\right)$
