x ------------ 2 x + 2*x - 3
x/(x^2 + 2*x - 3)
x ------------- 2 -3 + x + 2*x
x/(-3 + x^2 + 2*x)
1/(4*(-1 + x)) + 3/(4*(3 + x))
1 3 ---------- + --------- 4*(-1 + x) 4*(3 + x)
x ---------------- (-1 + x)*(3 + x)
x/((-1 + x)*(3 + x))
x -------------- -3 + x*(2 + x)
x/(-3 + x*(2 + x))
x/(-3.0 + x^2 + 2.0*x)