[tex] \frac{5}{ \sqrt{6} - 1} - \frac{5}{ \sqrt{6} + 1} = \frac{5 \times ( \sqrt{6} + 1) - 5 \times ( \sqrt{6} - 1) }{( \sqrt{6} - 1)( \sqrt{6} + 1)} = \frac{5 \sqrt{6} + 5 - 5 \sqrt{6} + 5}{( {( \sqrt{6}) }^{2} - {1}^{2} } = \frac{10}{6 - 1} = \frac{10}{5} = 2[/tex]