Question 730278
Please supply more information.  What tools do you have, or have you learned?  I would try the rational roots test to see there are no rational roots, then apply Cardano's Formula to find the roots.  Graphing it on a graphing calculator will show you the real roots, and supply you with a visual approximation.<P>
With Cardano's Formula I wouldn't work it out by hand, I would plug the equation into a calculator like at Wolfram Math.<P>
Without knowing the tools available to you, I cannot answer this question completely.