How do i find the roots of this polynomial equation? The polynomial equation is: $x^4-5x^3+5x^2+5x-6=0$. 
How do i simplify this equation so that i can find its roots.
Please, can anyone teach me how to find roots of equations of degree 4 and degree 3.

Hint. Look first for rational solutions: for a polynomial of degree $n$, 
$$a_n x^n+\cdots +a_1x+a_0$$
with integer coefficients, if $p/q\in\mathbb{Q}$ is a solution then $p$ divides $a_0$ and $q$ divides $a_n$.
In your case, a very "lucky" one I would say, try with the divisors of $-6$ (note that $a_n=1$) that is: $\pm 1$,$\pm2$,$\pm3$,$\pm6$.
