x + 9 81 ----- + 18*x + -- - 9 2 x x
81 9 + x -9 + 18*x + -- + ----- x 2 x
-9.0 + 18.0*x + 81.0/x + (9.0 + x)/x^2
3 2 / 3\ - 9*x + 81*x + x*\9 + x + 18*x / ---------------------------------- 3 x
2 3 9 - 9*x + 18*x + 82*x ----------------------- 2 x
81 x + 9 -9 + 18*x + -- + ----- x 2 x
9 + 82*x -9 + 18*x + -------- 2 x
2 3 9 - 9*x + 18*x + 82*x ----------------------- 2 x