x²-y²-3x-3y

来源:学生作业学帮网 编辑:学帮网 时间:2024/05/31 07:10:00

x²-y²-3x-3y

x²-y²-3x-3y
=(x-y)(x+y)-3(x+y)
=(x+y)(x-y-3)

问什么?

=(x+y)(x-y)-3(x+y)
=(x+y)(x-y-3)