因式分解2(x+1)²-(x+7);x²+xy-x-2y-2;(x²-5x+8)(x²-5x+2)+8

问题描述:

因式分解2(x+1)²-(x+7);x²+xy-x-2y-2;(x²-5x+8)(x²-5x+2)+8

2(x+1)²-(x+7)
=2x²+3x-5
=(2x+5)(x-1)
x²+xy-x-2y-2
=x²-x-2+xy-2y
=(x-2)(x+1)+y(x-2)
=(x-2)(x+1+y)
(x²-5x+8)(x²-5x+2)+8
=(x²-5x)²+10(x²-5x)+24
=(x²-5x+4)(x²-5x+6)
=(x-1)(x-4)(x-2)(x-3)