Respuesta :

Hippalectryon
Assuming you mean [tex]x^2+(y+3)^2=9[/tex], which is the equation of a circle :

the general equation of a circle of radius [tex]R[/tex] and center [tex](a,b)[/tex] is [tex](x-a)^2+(y-b)^2=R^2[/tex] hence here the center is [tex]\boxed{(0,-3)}[/tex]