\[f(x) = \frac{x^{2} + 5}{6x^{2}};\ \ \ \]
\[f(5) + f( - 5) = ?\]
\[f(5) + f( - 5) =\]
\[= \frac{25 + 5}{6 \cdot 25} + \frac{25 + 5}{6 \cdot 25} =\]
\[= \frac{30}{150} + \frac{30}{150} = \frac{1}{5} + \frac{1}{5} = \frac{2}{5} = 0,4.\]