How would I go about solving this sum for $x$?
$$\sum_i\frac{a_i}{(x+b_i)^2}=C$$
Where $\mathbf{a}$ and $\mathbf{b}$ are vectors and $C$ is a constant, and $x$ is a single number. It's for an optimisation routine so if there is no solution getting as close as possible is fine.