I have $$f(L) = M^{L-1} / (M+1) ^L $$ and $$ L = \log_M ((K+B)/A)$$
I am suppose to simply this to $$f = C(K+B)^{-b}$$ with $$ b = \dfrac{\ln(M+1) }{ \ln(M)}$$ for the top I have simplified $M^{L-1}$ to $\frac{K+B}{AM}$, but I have no idea how to simplify the bottom part. Some help would be great