Answer:
C 15
Explanation:
The equation of a circle is in the form
(x-h)^2 + (y-k)^2 = r^2
where (h,k) is the center and r is the radius
Since our equation is
(x-6)^2 + (y+5)^2 = 15^2
(x-6)^2 + (y- -5)^2 = 15^2
So the center is (6,-5) and the radius is 15