Use thevenin techniques to find the equivalent circuit (Rth and Vth) to which the points A + B are attached.
Kirchoffs loop rules
The Attempt at a Solution
I have indicated my chosen loops in blue. I am not quit sure at this point how to apply kirchoffs loop rule to each of the loops so that I can determine Vth. the only loop I felt confident on was number 1 i.e. 1: 5V-40ΩI1+Vth. There so much going on in the circuit that its hard from me to determine which way current is flowing so that I can create a junction rule for the wire between the yellow points. Any help would be greatly appreciated!