(x+1)(x-2)(x-3)(x-6)+20

问题描述:

(x+1)(x-2)(x-3)(x-6)+20
因式分解

=[(x+1)(x-6)][(x-2)(x-3)]+20 =[(x-5x)-6][(x-5x)+6]+20 =(x-5x)-36+20 =(x-5x)-16 =(x-5x+4)(x-5x-4) =(x-1)(x-4)(x-5x-4)