giovanni said:

I try a couple of educated guesses, but not 9!

 

I had to make an Excell sheet an having k going from 1 to 50, I finally got it (though I had problems with decimals)!

 

I still have no clue what the first equation means though....

It's the standard Church encoding of the natural numbers into pure lambda calculus.  If you've been exposed to it it's definitely easier than the other problem, since you just need to be familiar with the encoding, not actually solve anything.   =)