Here's the question you clicked on:
GiggleSquid
Find the center of this ellipse: 9x^(2)+y^(2)+36x-4y+31=0
@lgbasallote or @satellite73 you know these?
not good with graphs sorry
http://www.cccg.ca/proceedings/2005/49.pdf http://mathcentral.uregina.ca/QQ/database/QQ.09.06/s/sima1.html' http://www.purplemath.com/modules/ellipse2.htm
these are the worst references ever
9x^(2)+y^(2)+36x-4y+31=0 or, 9 (x^2+4x +4) +(y^2-4y+4)-9=0 or, 9(x+2)^2 + (y-2)^2 = 9 or, (x+2)^2 +(y-2)^2 /9 = 1.... see that the centre is (-2,2)
The purplemath.com reference is exactly what you need to do this.
what is wrong with @bhaweshwebmasters answer?
do you know how to complete the square? Thats all we are doing on these.