This is the actual PNG!

I am not certain what you need, it is straight forward.

a. Figure open circuit voltage Vab. That seems easy...you have V3+V2 equal to Vs Remember V3 has two currents thru it, 20ma + the current due to Vs. Vab= V3

Next, find short circuit current, you have Iab=I2-20mA

given that, you can deduce the Thevelin equivalent directly.

good question. i'll be looking into that. (this is a joke sir)

answer; to be the responsible party for healthcare delivery through medicare and medicaid programs;