C is (x + 2)2 + (y-7)2 = 36. What is its center (h, k)?

  (-2, 7)

Step-by-step explanation:

Compare the given equation to the form ...

  (x -h)^2 +(y -k)^2 = r^2

  (x +2)^2 + (y -7)^2 = 36

You can identify the following equivalences:

  -h = +2   ⇒   h = -2

  -k = -7   ⇒   k = 7

The center (h, k) is (-2, 7).