Question

Using the following equation, find the center and radius of the circle.
x^2 - 4x + y^2 + 8y = -4

I know it's got to do with the equation of a circle, but I don't know how to get from this equation to that. :S

Answer 1

Too much for me to type. You'll need completing the square here. I found you a page though.

http://www.purplemath.com/modules/sqrcircle.htm

Answer 2

Oh my gosh thank you, I'll try the steps on that page. You're a lifesaver lol.