Find the center and radius of each circle

Question

1. X^2 + y^2 = 36
2. (x+4)^2 + (y+6)^2 = 16

Answer 1

(x - h)² + (y - k)² = r²

(h,k) is the center

1. There is no h or k, so they both equal 0 (it would be silly to say (x - 0)², right?).

Center: (0,0)

Radius: 6

Center: (-4,-6) -----> x - (-4) = x + 4 and y - (-6) = y + 6

Radius: 4