Question 48982
{{{3x^3 + 15x^2 + 4x + 20}}}
a = 1,2,4,5,10,20
b = 1,3
Possible Roots: +-a/b = +- 1,2,4,5,10,20,1/3,2/3,4/3,5/3,10/3,20/3
Normally, you would try them out, but for a quicker way, look at the graph:
{{{graph(600,600,-10,10,-10,30,3x^3+15x^2+4x+20)}}}
-5|.....3......15.......4........20
..........3.......0........4.......0
(x + 5)(3x^2 + 4)