4 2 x - 20*x + 64 --------------- (x + 2)*(x - 4)
(64.0 + x^4 - 20.0*x^2)/((2.0 + x)*(-4.0 + x))
2 / 2\ 64 + x *\-20 + x / ------------------ (-4 + x)*(2 + x)
2 -8 + x + 2*x
(-2 + x)*(4 + x)