3. Вычислите: 1) 5/6 + 3/5 2) 11/12 - 1/4 3) 13/15 - 2/10 + 3/5

1) \(\frac{5}{6} + \frac{3}{5}\). Общий знаменатель 30. \(\frac{5}{6} = \frac{25}{30}\), \(\frac{3}{5} = \frac{18}{30}\). \(\frac{25}{30} + \frac{18}{30} = \frac{43}{30} = 1\frac{13}{30}\) 2) \(\frac{11}{12} - \frac{1}{4}\). Общий знаменатель 12. \(\frac{1}{4} = \frac{3}{12}\). \(\frac{11}{12} - \frac{3}{12} = \frac{8}{12} = \frac{2}{3}\) 3) \(\frac{13}{15} - \frac{2}{10} + \frac{3}{5}\). Общий знаменатель 30. \(\frac{13}{15} = \frac{26}{30}\), \(\frac{2}{10} = \frac{6}{30}\), \(\frac{3}{5} = \frac{18}{30}\). \(\frac{26}{30} - \frac{6}{30} + \frac{18}{30} = \frac{20}{30} + \frac{18}{30} = \frac{38}{30} = \frac{19}{15} = 1\frac{4}{15}\) Ответы: 1) \(1\frac{13}{30}\) 2) \(\frac{2}{3}\) 3) \(1\frac{4}{15}\)