The equation of a circle is written as (x-h)^2 + (y-k)^2 = r^2, wherein the center of the circle is at (h,k) and its radius is r. In this case, the circle has the center at (5, -3) with a radius of 5. Thus, the point (0,-3) is on the circle since this point is exactly 5 units to the left of the center of the circle which is equal to the radius of the circle.
