I really need some help on simplifying this math equation. Please help me reduce it as simple as possible! Thanks in advance!
$\large P_0=\frac{1}{\left[\sum_{i=0}^{M-1} \frac{1}{i!}\left(\frac{\lambda}{\mu}\right)^i\right]+\frac{1}{M!}\left(\frac{\lambda}{\mu}\right)^M\frac{M\mu}{M\mu-\lambda}}$