Step-by-step explanation:
If we have f(x) and it's inverse, and we compose them
we will get
[tex]f {}^{ - 1} (f(x) = x[/tex]
So here we compose
[tex]( \frac{1}{ \frac{1 + x}{x} - 1} )[/tex]
[tex]( \frac{1}{ \frac{1}{x} + 1 - 1} [/tex]
[tex] \frac{1}{ \frac{1}{x} } [/tex]
[tex]x [/tex]
So the composition is x, so they are inverses.