**Problem**

Solve the equation $$\frac{1}{x^2+11x-8} + \frac{1}{x^2+2x-8} + \frac{1}{x^2-13x-8} = 0$$

**What I've tried**

First I tried factoring the denominators but only the second one can be factored as $(x+4)(x-2)$.

Then I tried substituting $y = x^2 - 8$ but that didn't lead me anywhere.

**Where I'm stuck**

I don't know how to start this problem. Any hints?

P.S. I would really appreciate it if you give me *hints* or at least hide the solution. Thanks for all your help in advance!