Which is the equation of a circle with a radius of 6 and a center of (3,-1)?
(x - 3)2 + (y+1)2 = 36
(x+3)2 + (y - 1)2 = 36
(x+3)2 + (y - 1)2 = 6
(x-3)2 + (y+ 1)2 = 6