作业帮计算 (x-y)²-(x+y)(x-y)
来源：学生作业帮助网 编辑：作业帮 时间：2024/05/09 11:19:09
计算 (x-y)²-(x+y)(x-y)
计算 (x-y)²-(x+y)(x-y)
计算 (x-y)²-(x+y)(x-y)
(x-y)²-(x+y)(x-y)=x²+y²-2xy-(x²-y²)
=x²+y²-2xy-x²+y²
=2y²-2xy
(x-y)²-(x+y)(x-y)
=（x-y）（x-y-x-y）
=-2y（x-y）
原式=(x²-2xy+y²)-(x²-y²)
=x²-2xy+y²-x²+y²
=-2xy+2y²