5x^4-41x^3-87x^2-31x+10=0

Answer 1

I assume you want values of x which solve the equation.

Well, you know the rational roots will be of the form 1,2,5,10 or 1/5,2/5

A little synthetic division shows that x+1 divides twice, so you have

(x+1)(x+1)(5x^2-51x+10)

Now you can easily see that it is

(x+1)(x+1)(x-10)(5x-1) = 0