\[\frac{4b - 2a}{3} = \frac{2 \cdot (2b - a)}{3} \cdot \frac{( - 5)}{( - 5)} =\]
\[= \frac{2 \cdot (5a - 10b)}{- 15} =\]
\[= \frac{2 \cdot 18}{- 15} = \frac{- 12}{5} = - 2,4\]