/3*a - 9\ |-------| \ a + 2 / --------- / 2 \ |a - 9| |------| | 2 | \a - 4/
/ 2\ (-9 + 3*a)*\-4 + a / -------------------- / 2\ \-9 + a /*(2 + a)
(-4.0 + a^2)*(-9.0 + 3.0*a)/((2.0 + a)*(-9.0 + a^2))
/ 2\ 3*\-4 + a /*(-3 + a) -------------------- / 2\ \-9 + a /*(2 + a)
3*(-2 + a) ---------- 3 + a
15 3 - ----- 3 + a
/ 2 \ \a - 4/*(3*a - 9) ------------------ / 2 \ (a + 2)*\a - 9/