№2. Выполните действия: 1) $$\frac{3}{28} + \frac{15}{28} + \frac{11}{28}$$; 2) $$3\frac{7}{23} - 1\frac{4}{23} + 5\frac{9}{23}$$; 3) $$1 - \frac{17}{20}$$; 4) $$5\frac{3}{8} - 3\frac{5}{8}$$; 5) $$4\frac{2}{3} \cdot 1\frac{1}{7}$$; 6) $$3\frac{1}{5} : 2\frac{2}{15}$$.

1) \(\frac{3}{28} + \frac{15}{28} + \frac{11}{28} = \frac{3 + 15 + 11}{28} = \frac{29}{28} = 1\frac{1}{28}\) 2) \(3\frac{7}{23} - 1\frac{4}{23} + 5\frac{9}{23} = (3 - 1 + 5) + (\frac{7}{23} - \frac{4}{23} + \frac{9}{23}) = 7 + \frac{7 - 4 + 9}{23} = 7 + \frac{12}{23} = 7\frac{12}{23}\) 3) \(1 - \frac{17}{20} = \frac{20}{20} - \frac{17}{20} = \frac{20 - 17}{20} = \frac{3}{20}\) 4) \(5\frac{3}{8} - 3\frac{5}{8} = (5 - 3) + (\frac{3}{8} - \frac{5}{8}) = 2 - \frac{2}{8} = 2 - \frac{1}{4} = 1\frac{4}{4} - \frac{1}{4} = 1\frac{3}{4}\) 5) \(4\frac{2}{3} \cdot 1\frac{1}{7} = \frac{4 \cdot 3 + 2}{3} \cdot \frac{1 \cdot 7 + 1}{7} = \frac{14}{3} \cdot \frac{8}{7} = \frac{14 \cdot 8}{3 \cdot 7} = \frac{2 \cdot 8}{3} = \frac{16}{3} = 5\frac{1}{3}\) 6) \(3\frac{1}{5} : 2\frac{2}{15} = \frac{3 \cdot 5 + 1}{5} : \frac{2 \cdot 15 + 2}{15} = \frac{16}{5} : \frac{32}{15} = \frac{16}{5} \cdot \frac{15}{32} = \frac{16 \cdot 15}{5 \cdot 32} = \frac{1 \cdot 3}{1 \cdot 2} = \frac{3}{2} = 1\frac{1}{2}\)