hey guys could somebody please help me?

i have been on this problem for a while and i dont get any where.

The problem statement, all variables and given/known data

Prove that, for all integers n=>1

i get to the point where i need to prove that S(k+1) also true but what is k+1?

is it 1/k(k+1)(k+3)

or (k+1)(k+3)/(k+1)(k+3)(k+5)

we had one lesson on this and this home work is damn hard :'(

please somebody help me

thank you ever so much