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