在线等！若1/x=2,则x+2/3-4x=？

解：由已知得：x=1/2，则
x+2/3-4x
=1/2+2/3-4*1/2
=7/6-2
=-5/6

但如果题目是：(x+2)/(3-4x)=???的话，则答案为：
(x+2)/(3-4x)
=(1/2+2)/(3-4*1/2)
=5/2÷1
=5/2

-5/6

若1/x=2,则x+2/3-4x=？
1/x=2

x=1/2

(x+2)/(3-4x)

=(1/2+2)/(3-2)

=5/2

x=1/2
1/2+2/3-2=-5/6

悬赏分都没啊？！

1/x=2
x=0.5

原式=0.5+2/3-4*0.5