UC知道(X-3y)(x+3y)-(x-3y)^2
来源：百度知道 编辑：UC知道 时间：2024/05/15 18:15:56
快快!!有过程 谢!!
原式＝(x-3y)(x+3y-x+3y)
=6y(x-3y)
=6xy-18y^2
标准答案来了
(X-3y)(x+3y)-(x-3y)^2
=(x-3y)(x+3y)-(x-3y)(x-3y)
=(x-3y)[(x+3y)-(x-3y)]
=(x-3y)[x+3y-x+3y]
=(x-3y)(6y)
=6y(x-3y)
你要求什么？
=x^2-9y^2-x^2+6y-9y^2
=6y
原式＝(X-3Y)(X+3Y-X+3Y)
=(X-3Y)*6Y
=6XY-18Y^2
(X-3y)(x+3y)-(x-3y)^2=x^2-9y^2-（x^2-6xy+9y^2）=6xy-18y^2
6XY