Answer
$y^2=24(x+6)$
Work Step by Step
Vertex: $V(h,k)=V(-6,0)$
$h=-6$ and $k=0$
Equation of a parabola with horizontal axis and vertex at $(h,k)$:
$(y-k)^2=4p(x-h)$
$y^2=4p(x+6)$
The distance from the vertex to the directrix is equal to $p$. By observing the graph:
$p=-6-(-12)=6$
Finally:
$y^2=4(6)(x+6)$
$y^2=24(x+6)$
