I have to put the ellipse with the equation $\displaystyle ax^2+by^2+cx+dy+e=0$ into standard form, $\displaystyle \frac{(x-h)^2}{a}+\frac{(y-k)^2}{b}=1$

I have attached my work as a picture since it would take a long time to type in (I did it on Microsoft Office). Could anyone tell me if I am correct, and if not, where did I go wrong? Thanks!