2 x - x - 12 ----------- x + 3
(x^2 - x - 12)/(x + 3)
-4 + x
(-12.0 + x^2 - x)/(3.0 + x)
2 -12 + x - x ------------ 3 + x
(-12 + x^2 - x)/(3 + x)
-12 + x*(-1 + x) ---------------- 3 + x
(-12 + x*(-1 + x))/(3 + x)