6) (2 1/4 + 4 5/6) : 3 2/5 − 3/4 : 3/5

\(2\frac{1}{4}+4\frac{5}{6}=\frac{9}{4}+\frac{29}{6}=\frac{85}{12}\).

\(\frac{85}{12}:3\frac{2}{5}=\frac{85}{12}:\frac{17}{5}=\frac{25}{12}\).

\(\frac{3}{4}:\frac{3}{5}=\frac{3}{4}\cdot\frac{5}{3}=\frac{5}{4}\).

\(\frac{25}{12}-\frac{5}{4}=\frac{25}{12}-\frac{15}{12}=\frac{10}{12}=\frac{5}{6}\).

Ответ: \(\frac{5}{6}\)