To put formulae on here, use "LaTeX". see http://www.mathhelpforum.com/math-help/f47/
Now, to solve the equation, the first thing you do is cross your fingers and hope there is an rational number solution! By the "rational root theorem", any rational root of the polynomial equation is of the form where a is an integer that evenly divides the "constant term" and b is an integer that evenly divides the "leading coefficient" . Here, [tex]a_n[tex] is 1 so any rational root must be an integer that evenly divides 162. Fortunately, 162 does not have too many factors: .
So possible roots are . It is tedious, but not impossible, to try each of those.
(Good news! There is a simple integer root. Search for it. Once you have one factor, divide by it to get a quadratic equation you may be able to factor, or use the quadratic formula or complete the square to solve.)
(If there were no rational root, there is a "Cardano's formula", Cubic function - Wikipedia, the free encyclopedia
but it is very complex and tedious to use!)