Let $f(x)=\dfrac{x}{x-7}$. Find a function $y=g(x)$ so that $(f\circ g)(x)=x$.
Does anyone have any ideas on how to do this? I've exhausted all sorts of possibilities and I am now clueless. (On a side note, this is not homework, but rather an optional online assignment I was given. It's really puzzling me.)