Hi, x2+y2+16x+6y+9=0 x2+y2+16x+6y = -9 ||Completing the Square (x+8)^2 + (y + 3)^2 = -9 + 64 + 9 (x+8)^2 + (y + 3)^2 = 64 C (-8,-3), Circle with r = 8 Standard Form of an Equation of a Circle is where Pt(h,k) is the center and r is the radius