4x的前面是-吧,否则没法分解啊


x^4+x^3-3x^2-4x-4
=(x^4+x^3+x^2)-4x^2-4x-4
=x^2(x^2+x+1)-4(x^2+x+1)
=(x^2+x+1)(x^2-4)
=(x^2+x+1)(x+2)(x-2)