Let's suppose the following circuit: ![enter image description here][1] I am trying to find a relation between Vs, V1 and V2 at this circuit. Please note that Vs is measured in relation to the ground. I have declared some extra points (A,B,C) on the circuit and using voltage divider laws and the properties of an ideal operational amplifier I came up with the following solution: ![enter image description here][2] Is this correct? Another solution with a different result is the following: ![enter image description here][3] I am really confused. [1]: https://i.sstatic.net/1db4t.png [2]: https://i.sstatic.net/f7DrA.png [3]: https://i.sstatic.net/zyxuF.png