(9x^3+18x^2-x+2)/(3x+1) = 3x^2 + 5x - 2 + 4/(3x + 1)
3x^2 + 5x - 2
-------------------------------
3x + 1 (9x^3+18x^2-x+2)
9x^3 + 3x^2
- -
-----------------------------
15x^2 - x + 2
15x^2 + 5x
- -
----------------------
- 6x + 2
- 6x - 2
+ +
---------------
4