\[\frac{4x + y}{5x - 4y};\ \ если\ \ x = - 4,\ y = 2.\]
\[\frac{4x + y}{5x - 4y} = \frac{4 \cdot ( - 4) + 2}{5 \cdot ( - 4) - 4 \cdot 2} =\]
\[= \frac{- 16 + 2}{- 20 - 8} = \frac{- 14}{- 28} = \frac{1}{2} = 0,5.\]