若y/x-5y=1,则2x-3xy-2y/x-2xy-y的值是 _ .
问题描述:
若
-5y=1,则y x
的值是 ___ .2x-3xy-2y x-2xy-y
答
∵
-5y=1,∴y x
=5y+1,y x
把
的分子与分母同时除以x得:2x-3xy-2y x-2xy-y
=
=2-3y-2
y x 1-2y-
y x
2-3y-2(5y+1) 1-2y-(5y+1)
=
.13 7
故答案为:
.13 7