Find the coordinates of the vertices and foci and sketch the graph:

4x^2 + 9y^2 - 32x - 36y + 64 = 0

I tried completing the square and got:

4x^2 - 32x + 256 + 9y^2 - 36y + 324 = 516

but I cant factorise the x and y, since there seem to be no roots