4 2 x - 13*x + 36 --------------- 2 x - 4
(36.0 + x^4 - 13.0*x^2)/(-4.0 + x^2)
2 / 2\ 36 + x *\-13 + x / ------------------ 2 -4 + x
2 -9 + x
(-3 + x)*(3 + x)