Question

Is (3x-2) a factor of 3x^3+x^2-20x+12?

Answer 1

3x^3+x^2-20x+12

put x=2/3

3(2/3)^3+(2/3)^2-20(2/3)+12

3(8/27)+(4/9)-40/3+12

24/27+(4/9)-40/3+12

8/9+4/9-40/3+12

12/9-40/3+12

(12-120)/9+12

-108/9+12

(-108+108)/9

0