The equation of a circle:
[tex](x-h)^2+(y-k)^2=r^2[/tex]
(h,k) - the coordinates of the center
r - the radius
[tex]\hbox{the center: } (-2,-3) \\
h=-2 \\ k=-3 \\ \\
\hbox{the radius: } 3 \ units \\
r=3 \\ \\ \hbox{the equation:} \\
(x-(-2))^2+(y-(-3))^2=3^2 \\
\boxed{(x+2)^2+(y+3)^2=9}[/tex]