2x^4-x^3-11x^2-x+2
=2x^4+4x^3-5x^3-10x^2-x^2-2x+x+2
=(x+2)(2x^3-5x^2-x+1)
=(x+2)(2x^3+x^2-6x^2-3x+2x+1)
=(x+2)(2x+1)(x^2-3x+1)