2 x - 2*x - 15 ------------- 2 x + 6*x + 9
(-15.0 + x^2 - 2.0*x)/(9.0 + x^2 + 6.0*x)
-15 + x*(-2 + x) ---------------- 9 + x*(6 + x)
-5 + x ------ 3 + x
8 1 - ----- 3 + x