2x squared+2y squared+28x+80=0?

Question

A circle is defined by the following equation:
2x squared+2y squared+28x+80=0
What are the coordinates of its center?
Enter as an order pair.

Answer 1

2x^2 + 2y^2 + 28x + 80 = 0
x^2 + 14x + y^2 + 40 = 0
x^2 + 14x + 49 + y^2 = 49 - 40
(x+ 7)^2 + y^2 = 9
Xc,Yc = (-7,0), R = 3