计算 (x-y)²-(x+y)(x-y)

来源:学生作业帮助网 编辑:六六作业网 时间:2024/11/15 10:20:36
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)=x

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