You can put this solution on YOUR website! Complete The Square for the x and for the y, and then simplify into whichever standard for will be suitable to the type of conic section.
And continuing without explanation for this step section,
The squares are now completed.
Compare that to standard form of an ellipse: ,
where a is the distance from either vertex to the center along the x axis, b is the distance from either vertical vertex to the center along the y axis; if assuming center were on the origin --- although for YOUR example, center is NOT...
Standard Form for ellipse conventionally uses a for the longer axis and b for the shorter axis.
and the center point is (h,k).