Question 33784
It is difficult to know what to tell you.  It depends
on what tools you have available.
If you have a graphing calculator, use it to find 
a zero of the polynomial.  I find x=(-1/3).
Then using long division by (3x+1) or using synthetic
division you find the quotient is x^2-2x-2.
Use the quadratic formula on that to find x=1+sqrt3 or
x=1-sqrt 3.  You now have three zeroes.
Cheers,
Stan H.