How to find the vo in terms of v1 and v2?

[haha1234]

Homework Statement

The problem is upload below.

Homework Equations

The Attempt at a Solution

I was stuck at finding the voltage between the 100k resistor and 200k resistor.
Is the voltage zero since the node below there is zero and there is no resistor between them?
But if the node voltage is zero,there will be no current going through that path which I think is quite strange...

 

[berkeman]

Homework Statement

The problem is upload below.

Homework Equations

The Attempt at a Solution

I was stuck at finding the voltage between the 100k resistor and 200k resistor.
Is the voltage zero since the node below there is zero and there is no resistor between them?
But if the node voltage is zero,there will be no current going through that path which I think is quite strange...

For an ideal opamp with negative feedback, what can you say about the voltage difference between the + and - inputs?

I would solve this using KCL equations. Write the 3 KCL equations for the following nodes: - input of opamp, output of opamp, Vo node...

 

[CWatters]

Is the voltage zero since the node below there is zero and there is no resistor between them?

Which node do you mean by "the node below there"?

Perhaps see if "virtual Ground" is in your textbook.