Let $f(x) = (x-a_1)(x-a_2)...(x-a_n)$.
Find a decomposition into simple fractions of $\frac{f'}{f}$.
Where $f'$ is a derivative of our polynomial.
As I understand, we have to find a pretty-format of $f'$ and then task will be easy. But I have no idea how to find this.
Note that some $a_i$ can be equal to each other.