Найдите значение дроби (2x+8y)/(x^2-16y^2), если 4y-x=1/5.

\[\frac{2x + 8y}{x^{2} - 16y^{2}} = \frac{2(x + 4y)}{(x - 4y)(x + 4y)} =\]

\[= \frac{2}{x - 4y} = - \frac{2}{4y - x};\]

\[4y - x = \frac{1}{5}:\]

\[- 2\ :\frac{1}{5} = - 2 \cdot 5 = - 10.\]