What is the inverse of number 19 and how do you get the inverse?

I hope this helps you

19)

f (x)=1/x-1

f (x).x-f (x)=1

x=1+f (x)/f (x)

x=1+1//f (x)

f^-1 (x)=1+1/x

22)

f (x)-1=x^1/3

[f (x)-1]^3=(x^1/3)^3

x=[f (x)-1]^3

f^-1 (x)=(x-1)^3