If x+iy equal to root a+ib / c+id , prove that (x square + y square) whole square equal a^2 + b^2

If x+iy equal to root a+ib / c+id , prove that (x square + y square) whole square equal a^2 + b^2

If x+iy equal to root a+ib / c+id , prove that (x square + y square) whole square equal a^2 + b^2 / c^2 + d^2 .