3 x - 1 ------ 2 x + x
(-1.0 + x^3)/(x + x^2)
3 -1 + x --------- x*(1 + x)
/ 2\ (-1 + x)*\1 + x + x / --------------------- x*(1 + x)
-1 + x -1 + x + ------ 2 x + x