Question

What equation represents a circle whose center is located at (-6,2) and whose radius is 10 units?

Answer 1

One of the equations for a circle is (x - h)² + (y - k)² = r² where (h, k) are the center and r is the radius.
So after substitution:
(x + 6)² + (y - 2)² = 100

Notice the equation has the opposite of h and k and 100 is the result of squaring 10.