\[3x - 9y = 1 \Longrightarrow x - 3y = \frac{1}{3}\]
\[\frac{12y - 4x}{5} = \frac{4 \cdot (3y - x)}{5} =\]
\[= \frac{- 4 \cdot \frac{1}{3}}{5} = \frac{- \frac{4}{3}}{5} = - \frac{4}{15}\]