The equation x^2+6x+y^2+6y=18 represents a circle. What is its center?

\(x^2 + 6x + y^2 + 6y = 18\\ (x-3)^2 - 9 + (y-3)^2 - 9 = 18\\ (x-3)^2 + (y-3)^2 = 36 = 6^2\\ \text{center at }(3,3), \text{ radius 6}\)

Imnotamaster.

Why did you vote Rom's answer down ?

WHAT IS YOUR PROBLEM ?

Rom's answer is good and you should have thanked him and given him a point.

If you do not understand an answer then you SAY SO and ask for further explanation!