珠海井岸步行街小姐:shuxueti

来源:百度文库 编辑:查人人中国名人网 时间:2024/05/15 02:13:25
已知 1/x - 1/y =3,则分式 2x+3xy-2y/x-2xy-y 的值为?

由:1/x - 1/y =3
则:(x-y)/xy=3
(x-2xy-y)/xy=1
xy/(x-2xy-y)=1
所以:
2x+3xy-2y/x-2xy-y
=2+[7xy/(x-2xy-y)]
=2+7
=9