Answer
$(x+2)^2+(y-3)^2=225$
Work Step by Step
Center-radius form of equation of a circle is:
$$(x-h)^2+(y-k)^2=r^2$$
Where $(h,k)$ is a center and $r$ is a radius.
The given is center $(-2,3)$ and radius $r=15$. The equation becomes:
$$(x-(-2))^2+(y-3)^2=15^2$$
$$(x+2)^2+(y-3)^2=225$$
