The question is:

Let f(x) = 1/(1 + x). What is:

(i) f(f(x))

I think it's supposed to be f(f(x)) = 1/[1+(1/(1 + x))]

But the answers say that it's (x + 1)/(x + 2)

If I re-arrange the equation, the best I can get is (x + 1)/2, where does the extra x come from (if I'm even doing it right at all in the first place)?