Find the Thevenin equivalent circuit at terminals (a,b) for the circuit below.
The Attempt at a Solution
I am having a conceptual issue for this circuit. I can't combine any of the resistors, and my gut is telling me that something about the fact that its between terminals (a,b) means that one of these resistors can be neglected and essentially erased. However, I don't understand how that works as far as what signs I should look for and what should be neglected.
I removed all the sources in an attempt to find the thévenin equivalent resistance.