Answer - 53


1 comment:

Benjamin Leis said...

It might be a bit more mechanical to use the rational roots theorem to
find -1 and then just do some polynomial division

x^4 + x^3 + x + 1 | x + 1 = x^3 + 1

So the full factorization is:

(x+1)(x+1)(x^2 - x + 1) and only the first 2 parts have rational roots.