2 Вычислите: a) \(- \frac{3}{4} + \frac{6}{7}\); б) \(3\frac{5}{5} - 2\frac{2}{5}\); в) \(1\frac{2}{3} \cdot \frac{3}{10}\); г) \(\frac{3}{8} : 2\frac{1}{4}\)

a) \(- \frac{3}{4} + \frac{6}{7} = -\frac{21}{28} + \frac{24}{28} = \frac{3}{28}\) б) \(3\frac{5}{5} - 2\frac{2}{5} = 4 - \frac{12}{5} = \frac{20}{5} - \frac{12}{5} = \frac{8}{5} = 1\frac{3}{5}\) в) \(1\frac{2}{3} \cdot \frac{3}{10} = \frac{5}{3} \cdot \frac{3}{10} = \frac{15}{30} = \frac{1}{2}\) г) \(\frac{3}{8} : 2\frac{1}{4} = \frac{3}{8} : \frac{9}{4} = \frac{3}{8} \cdot \frac{4}{9} = \frac{12}{72} = \frac{1}{6}\)