I have to get a better understanding of Thevenin's theorem and have been unable even with the help of a tutor to come up with the Rth specified by my textbook for the following circuit: Vs--50V R1=22 Ohms || R2=22 Ohms, leading at the first node to R3=47 Ohms, then to the second node R4=33 Ohms. I've just started to learn how to Thevenize a circuit, and looking back from the open terminals, the circuit looks like this: ___22___ _____| |______*______________A +| |__22___| | 50| | -| 47 | | |_______33__________|______________B I apparently got the right Vth by using the voltage divider formula (47/91) x 50V. But when I tried to get the "right" (according to the textbook) Rth of 22.7, there was no way I could get that. Looking back from the open terminals, I put 11 Ohms (the first two resistors equivalent resistance) in parallel with 47, then that in parallel with 33. I continually came up with an answer of approximately 7.01, not 22.7. If anyone could tell me what I did wrong, I would appreciate greatly hearing from you here on this group. Thanks greatly.