Divide 3x 3 - 2x 2 - 61x - 20 by x - 5.

edit : the rest is zero : la console is right, but, after check : 
it's : 3x^2 + 13x + 4 and not + 5 (degree 0 term) 

3x^3 - 2x^2 - 61x - 20 | x - 5 
-3x^3+15x^23x^2 + 13x + 4 
13x^2 - 61x -20 
-13x^2 +65x 
4x -20 
-4x +20 
0 

finally : 

(3x^3 - 2x^2 - 61x - 20) / (x - 5) = 3x^2 + 13x + 4 

Hope this helps any sorry how its all scattered