(x+y)×(x-y)+(x-y)的平方-(x平方-3xy)等于多少,大哥大姐帮帮忙啊

来源:学生作业帮助网 编辑:作业帮 时间:2024/05/13 17:01:23
(x+y)×(x-y)+(x-y)的平方-(x平方-3xy)等于多少,大哥大姐帮帮忙啊

(x+y)×(x-y)+(x-y)的平方-(x平方-3xy)等于多少,大哥大姐帮帮忙啊
(x+y)×(x-y)+(x-y)的平方-(x平方-3xy)等于多少,大哥大姐帮帮忙啊

(x+y)×(x-y)+(x-y)的平方-(x平方-3xy)等于多少,大哥大姐帮帮忙啊
(x+y)(x-y)+(x-y)²-(x²-3xy)
=(x-y)[(x+y)+(x-y)]-x(x-3y)
=2x(x-y)-x(x-3y)
=x[2(x-y)-(x-3y)]
=x(x+y)

x(x+y)

(x+y)(x-y)+(x-y)"-(x"-3xy)=(x-y)[(x+y)+(x-y)]-x(x-3y)=2x(x-y)-x(x-3y)=x"-xy("是平方)