当1/x+2/y=5时,求代数式2x+xy+y/8x-3xy+4y的值（过程!

来源：学生学帮网编辑：学帮网时间：2024/06/14 11:42:11

1/x+2/y=5,
则y/(xy)+2x/(xy)=5
(2x+y)/(xy)=5
2x+y=5xy
则2x+xy+y/8x-3xy+4y
=2x-y+xy/4(2x-y)-3xy
=5xy+xy/20xy-3xy
=6xy/17xy
=6/17