x^5+x-1 = x^5+x^2-x^2+x-1 = x^2(x^3+1)-(x^2-x+1) = (x^3+x^2-1)(x^2-x+1)
X(X^4+X-1)X(X^2-1)^2X(X-1)^2*(X+1)^2
