You can put this solution on YOUR website! That is a lovely equation with two unknowns.
There is no solution because there are two unknowns.
So what is your question?
-x^2-y^2+10x+12y-36=0
-(x-5)^2-(y-6)^2+25 = 0
(x-5)^2+(y-6)^2=25
(1/25(x-5)^2)+(1/25 (y-6)^2) = 1