I'm trying to determine the Thevenin equivalent circuit for the attached circuit. Also, the value of the load resistance R load for maximum power transfer. I'm not to sure how exactly the Thevenin theorem operates but I simply added my resistor in series and parallel (where appropriate). I suppose that gave me "R equivalence" which equaled 15 ohms. Not sure if that is correct after shorting out the voltages and open the currents (zeroing out). Can someone help figure the "load resistance for max. power transfer?" I'm attaching the diagram here.