已知x+y分之xy=2,那么3x-5xy+3y分之3xy-x-y=

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/23 16:45:31
已知x+y分之xy=2,那么3x-5xy+3y分之3xy-x-y=
xA 0EZH(]&ٺp!^@e9g]u"y]+u( ,ilL&!ӚTF=S ߢd

已知x+y分之xy=2,那么3x-5xy+3y分之3xy-x-y=
已知x+y分之xy=2,那么3x-5xy+3y分之3xy-x-y=

已知x+y分之xy=2,那么3x-5xy+3y分之3xy-x-y=
xy/(x+y)=2
∴xy=2(x+y)
(3xy-x-y)/(3x-5xy+3y)
=[6(x+y)-x-y]/[3x+3y-10(x+y)]
=5(x+y)/[-7(x+y)]
=-5/7

2(X+Y)=XY
3XY-X-Y/3X-5XY+3Y
=3XY-(X+Y)/3(X+Y)-5XY
=6(x+y)-(x+y)/3(x+y)-5*2(x+y)
=5(x+y)/(-7)(x+y)
=-5/7