[tex]\displaystyle \int \dfrac{1}{5x^2-125} = \dfrac{1}{5}\int \dfrac{1}{x^2-25} = \dfrac{1}{5} \cdot \dfrac{1}{10} \cdot \ln \left | \dfrac{x-5}{x+5} \right|=\dfrac{1}{50} \cdot \ln \left | \dfrac{x-5}{x+5} \right|[/tex]
