Differentiate the function f(t) = ln [(2t+1)^3 / (3t-1)^4]

Hi, ok. Let me explain you:

Firstly, we have:
f−1(f(x))=f(f−1(x))=x

We' are going to use this to find f−1(x)
then f(x)=5x−3
to find f−1(x)
so, we put x= f−1(x),
and we havef(f−1(x))=5f−1(x)−3
thus, we get x=5f−1(x)−3                           5f−1(x)=x+3 or maybef−1(x)=x+35