# Math Help - circle equation

1. ## circle equation

Can someone explain to me how to find the center and radius of the circle: (x+5)^2 + (y-5)^2 = 100 ???
I'm a little confused.

2. The equation of a circle of radius $r$ and the center in the point of coordinations $(a,b)$ is
$(x-a)^2+(y-b)^2=r^2$
So, you must to identify $a,b,r$. Can you do it?