Hi, The question I have is:

Express a single generality that generalises all three related observations that

and show that your generalisation always holds true.

I know that the answer (i.e. RHS of =) is always (supposed to say no. of different terms)

I also know that LHS is , where a=1

but I'm not sure how to show all of this generally, so that it works for every case . Any ideas?