Problem understanding Thévenins equivalent circuit

[Pellefant]

Problem understanding "Thévenins equivalent circuit "

The problem is illustrated in the picture below.

http://img266.imageshack.us/img266/5422/thevininprobxn1.jpg

I am not sure i understand this so well either, any comments are appriciated.

Best regards

Pellefant

 

[Defennder]

Your answers are missing a factor of I1.

How did you get I(SC) = (B+E)I1/(C+B+E) ?

To get the answer just consider the mesh equation equations set up for the loop on the left with the voltage source, A and C in clockwise. Then, remembering that D is shorted, set up another mesh equation with the voltage source, A, B, E clockwise. Equate the two equations to eliminate the voltage source and you're done.