\[x - 2y = 5;\ \ m = 3:\]
\[\frac{3 \cdot (x - 2y)}{m + 2 \cdot (2y - x)} =\]
\[= \frac{3 \cdot 5}{3 + 2 \cdot ( - 5)} = \frac{15}{3 - 10} =\]
\[= \frac{15}{- 7} = - 2\frac{1}{7}.\]