Упрости выражение: 5/7*(2,8c-4 1/5*d)-2,4*(5/6*c-1,5d).

\[\frac{5}{7} \cdot (2,8c - 4d) - 2,4 \cdot (\frac{5}{6}c - 1,5d) =\]

\[= \frac{5}{7} \cdot \frac{28}{10}c - \frac{5}{7} \cdot \frac{21}{5}d - \frac{24}{10} \cdot \frac{5}{6}c + \frac{24}{10} \cdot \frac{15}{10}d =\]

\[= 2c - 3d - 2c + \frac{18}{5}d = \frac{18}{5}d - 3d =\]

\[= d(3,6 - 3) = 0,6d\]