(x²-x-3)²-(x²-x-3)-3-x
=(x²-x-3)²-x²
=(x²-x-3-x)(x²-x-3+x)
=(x²-2x-3)(x²-3)
=(x-3)(x+1)(x²-3)
=(x-3)(x+1)(x+根号3)(x-根号3)