While reading the proof of Cauchy's integral formula I didn't quite understand why is $f(z)/(z-a)$; $z$ $\in$ {$\mathbb{C}$ $\neq$ $a$} holomorphic if $f(z)$ is holomorphic. I tried to prove it to myself using Cauchy-Riemann equations, but the terms didn't quite add up.
Can somebody please prove it to me using the equations or any other method?
Since the quotient of two holomorphic functions is holomorphic and since you are explicitely excluding $a$ from the domain, $\frac{f(z)}{z-a}$ is holomorphic too.