Question 252189
We want to find f(f(x)). We use order of operations and always start from the inner most parenthesis. We can rewrite f(f(x)) as

{{{f(x / (1-x))}}}

which means where ever you see an X, put X/ 1-X. We get

{{{X/(1-X)}}} / {{{(1-X/(1-X))}}}

simplifying the large denominator, we get

{{{X/(1-X)}}} / {{{((1-2X)/(1-X))}}}

multiplying by the reciprocal, we get

X / (1-2X).