**What is the resistance Rx, in order to have Vo/Vs=1/2**

[![enter image description here](https://i.stack.imgur.com/Tbv8f.png)](https://i.stack.imgur.com/Tbv8f.png)

Hi, my teacher asked us to solve this question, keep In mind that i'm not asking for you to do my homework, I think is just a impossible question, i've tried every possible method for solving it with no success, and I really need to solve it for my pontuation.

First i've tried **Mesh** Analysis with no success.

Second i've tried **Node** Analysis with no sucess.

Then i've tried **Voltage divider** with no sucess also.

[Mesh, Node and Voltage Divider Analisys](https://i.stack.imgur.com/E7U0I.png)

**If Rx value is zero, the Voltage Source is short circuited. I don't know what else to do.**