Please click the image to enlarge it I'm having trouble seeing how this circuit was reduced. Can anyone shed some light on it for me? My question pertains to the second solution in the image. I see that the 12k and 4k resistors are in parallel and that leads to the second diagram on the bottom. Why is the 6k resistor drawn up there? When I try to redraw the circuit, I keep it just like the first one- with the exception that the 12k and 4k resistors are combined on the rightmost branch- with the 6k and the current source in the same place. When the 6V source is shorted out why is there a need to redraw that branch?