猎人 宠物buff:初一数学题

来源:百度文库 编辑:查人人中国名人网 时间:2024/04/16 14:37:28
若1/x - 1/y=2,求(3x-2xy-3y)/(x-2xy-y)的值
要有步骤

上下同除以xy
(3/y-2-3/x)/(1/y-2-1/x)=(-6-2)/(-2-2)=2

你怎么那么懒啊

1/x - 1/y =3
(y-x)/xy =3
y-x =3xy
(3x-2xy-3y)/ (x-2xy-y)
=(3(x-y)-2xy )/((x-y)-2xy)
=(4*-3xy-2xy)/(3*-3xy-2xy)
=-14/(-11)
=14/11