Summation proof, PLEASE HELP!?

Question

I have to prove a summation and I don't even know where to start

here's the link to it

http://s391.photobucket.com/albums/oo354/jet0l19/?action=view&current=proof.jpg

thanks a lot

Answer 1

You can do it several ways.  You can show that each element in one sum appears exactly once in the other... or you can do induction on n... your choice.