Please stay on topic. Discussions irrelevant to the topic at hand can be carried out via private messaging.

I look at completing the square like a quadratic,

e.g.

x^2 +2x+4 which can be factorised easily. You need to make the equation

5x2 + 132x + 6y2 + 99y + 56 = 770 into this to factorise. I just bring similar values together, by moving it around.

and then you HALVE the coefficent of x and y respectively and double them. Then you add this value to Each side of the equation.

The factorise and you should have the equation. For a circle,

I used (x-h)^2 + (y-k)^2 = r^2 which can be easily gained from rearranging the left side to squared form, right should be correct from above.

Worked for me,

hope it helps.

By the way I got this out of my books which I am selling at

http://community.boredofstudies.org/showthread.php?t=295911 REALLY cheap, if you want have a look.