3 (2$$\frac{5}{6}$$\cdot$$\frac{3}{7}$$-$$\frac{8}{25}$$:0,4)$$\cdot$$2$$\frac{1}{17}$$+3$$\frac{4}{7}$$\cdot$$0,28

Выполним действия по шагам: 1) $$2\frac{5}{6} = \frac{17}{6}$$ 2) $$\frac{17}{6} \cdot \frac{3}{7} = \frac{17}{2 \cdot 7} = \frac{17}{14}$$ 3) $$\frac{8}{25} : 0,4 = \frac{8}{25} : \frac{4}{10} = \frac{8}{25} \cdot \frac{10}{4} = \frac{2 \cdot 2}{5} = \frac{4}{5}$$ 4) $$\frac{17}{14} - \frac{4}{5} = \frac{17 \cdot 5}{14 \cdot 5} - \frac{4 \cdot 14}{5 \cdot 14} = \frac{85}{70} - \frac{56}{70} = \frac{29}{70}$$ 5) $$2\frac{1}{17} = \frac{35}{17}$$ 6) $$\frac{29}{70} \cdot \frac{35}{17} = \frac{29 \cdot 1}{2 \cdot 17} = \frac{29}{34}$$ 7) $$3\frac{4}{7} = \frac{25}{7}$$ 8) $$\frac{25}{7} \cdot 0,28 = \frac{25}{7} \cdot \frac{28}{100} = \frac{25 \cdot 4}{100} = 1$$ 9) $$\frac{29}{34} + 1 = 1\frac{29}{34}$$ Ответ: $$1\frac{29}{34}$$