2*x - 1 -------- 2 (x + 1)
(2*x - 1)/(x + 1)^2
-3/(1 + x)^2 + 2/(1 + x)
3 2 - -------- + ----- 2 1 + x (1 + x)
(-1.0 + 2.0*x)/(1.0 + x)^2
-1 + 2*x ------------ 2 1 + x + 2*x
(-1 + 2*x)/(1 + x^2 + 2*x)