(x+y)(x-y)-(x+y)²怎么提公因式

问题描述:

(x+y)(x-y)-(x+y)²怎么提公因式

把相同的提出来,(x+y)(x-y)-(x+y)^2=(x+y)(x-y-x-y)=-2y(x-y)。

(x+y)(x-y —(x+y))

(x+y)(x-y)-(x+y)²
=(x+y)[(x-y)-(x+y)]
=(x+y)(-2y)
=-2y(x+y)

原式=(x+y)[(x-y)-(x+y)]
=-2y(x+y)