Find the center-radius form of the equation of the circle described. Then graph the circle. Center (0,0), radius 8

If the center is (0, 0), then there is no side to side or up or down motion. The center is at the origin. The standard form of a circle is (x-h) ^2 + (y-k) ^2 = r^2. Your h and your k are both 0's, so just fill in and square the radius:

x^2 + y^2 = 64