y 1 y + - - y + -- - x x 2 x
y + y/x - y + 1/(x^2) - x
1 y -- - x + - 2 x x
x^(-2) - x + y/x
3 1 - x + x*y ------------ 2 x
(1 - x^3 + x*y)/x^2
1 + x*y -x + ------- 2 x
-x + (1 + x*y)/x^2
4 2 x - x + y*x ------------- 3 x
(x - x^4 + y*x^2)/x^3
/ 3 \ -\-1 + x - x*y/ ----------------- 2 x
-(-1 + x^3 - x*y)/x^2