Given a function:
[tex]f(x)=9x-9[/tex]
We have to find the value of:
[tex](f\circ f^{-1})(-9)[/tex]
It is known that if f is an invertible function, then
[tex](f\circ f^{-1})(x)=x_{}[/tex]
So, here:
[tex](f\circ f^{-1})(-9)=-9[/tex]
Thus, the answer is -9.
