学帮网(x+y)³-(x-y)²(x+y)
来源：学生作业学帮网 编辑：学帮网 时间：2024/06/05 09:12:26
(x+y)³-(x-y)²(x+y)
(x+y)³-(x-y)²(x+y)
=(x+y)(x+y)²-(x-y)²(x+y)
=(x+y)[(x+y)²-(x-y)²]
=（x+y）*4xy
=4xy(x+y)
(x+y)³-(x-y)²(x+y)
=（x+y）[（x+y）^2-(x-y）^2]
=(x+y）（x+y+x-y）（x+y-x+y）
=(x+y）2x*2y
=4xy（x+y）
(x+y)³-(x-y)²(x+y)
=(x+y)[(x+y)²-(x-y)²]
=(x+y)[(x+y)+(x-y)][(x+y)-(x-y)]
=(x+y)(x+y+x-y)(x+y-x+y)
=4xy(x+y)