If xy equals x2 plus y2 plus 2xy?

Answer 1

If:

xy = x2 + y2 + 2xy

Then:

x2 + xy + y2 = 0

Do you want to solve it for x?

x2 + xy + (y/2)2 = (y/2)2 - y2

(x + y/2)2 = y2/4 - y2

x + y/2 = ± √(-3y2/4)

x = -y/2 ± y√(-3) / 2

x = (-y ± yi√3) / 2