(x的平方-3x-3)(x的平方-3x+4)-8
=(x²-3x)²+(x²-3x)-20
=(x²-3x+5)(x²-3x-4)
=(x²-3x+5)(x-4)(x+1)
x(x-1)(x+1)(x+2)-24
=[x(x+1)][(x-1)(x+2)]-24
=(x²+x)(x²+x-2)-24
=(x²+x)²-2(x²+x)-24
=(x²+x-6)(x²+x+4)
=(x+3)(x-2)(x²+x+4)