4. Выполните действия а) \(\frac{7}{8} - \frac{1}{6}\) б) \(\frac{7}{9} + \frac{5}{15}\) в) \(\frac{3}{4} \cdot \frac{2}{9}\) г) \(\frac{3}{14} : \frac{3}{7}\) д) 3 + 2\(\frac{4}{7}\) е) 2 - 1\(\frac{5}{6}\) ж) 3\(\frac{3}{4}\) \cdot 1\(\frac{1}{9}\) з) 2 : 1\(\frac{2}{5}\)

Разберем все действия по порядку. а) \(\frac{7}{8} - \frac{1}{6}\) = \(\frac{7 \cdot 3}{8 \cdot 3} - \frac{1 \cdot 4}{6 \cdot 4}\) = \(\frac{21}{24} - \(\frac{4}{24}\) = \(\frac{21 - 4}{24}\) = \(\frac{17}{24}\) б) \(\frac{7}{9} + \frac{5}{15}\) = \(\frac{7}{9} + \frac{1}{3}\) = \(\frac{7}{9} + \frac{1 \cdot 3}{3 \cdot 3}\) = \(\frac{7}{9} + \frac{3}{9}\) = \(\frac{7 + 3}{9}\) = \(\frac{10}{9}\) = 1\(\frac{1}{9}\) в) \(\frac{3}{4} \cdot \frac{2}{9}\) = \(\frac{3 \cdot 2}{4 \cdot 9}\) = \(\frac{6}{36}\) = \(\frac{1}{6}\) г) \(\frac{3}{14} : \frac{3}{7}\) = \(\frac{3}{14} \cdot \frac{7}{3}\) = \(\frac{3 \cdot 7}{14 \cdot 3}\) = \(\frac{21}{42}\) = \(\frac{1}{2}\) д) 3 + 2\(\frac{4}{7}\) = 3 + \(\frac{2 \cdot 7 + 4}{7}\) = 3 + \(\frac{14 + 4}{7}\) = 3 + \(\frac{18}{7}\) = 3 + 2\(\frac{4}{7}\) = 5\(\frac{4}{7}\) е) 2 - 1\(\frac{5}{6}\) = 2 - \(\frac{1 \cdot 6 + 5}{6}\) = 2 - \(\frac{11}{6}\) = \(\frac{2 \cdot 6}{6} - \frac{11}{6}\) = \(\frac{12}{6} - \frac{11}{6}\) = \(\frac{12 - 11}{6}\) = \(\frac{1}{6}\) ж) 3\(\frac{3}{4}\) \cdot 1\(\frac{1}{9}\) = \(\frac{3 \cdot 4 + 3}{4}\) \cdot \(\frac{1 \cdot 9 + 1}{9}\) = \(\frac{15}{4}\) \cdot \(\frac{10}{9}\) = \(\frac{15 \cdot 10}{4 \cdot 9}\) = \(\frac{150}{36}\) = \(\frac{25}{6}\) = 4\(\frac{1}{6}\) з) 2 : 1\(\frac{2}{5}\) = 2 : \(\frac{1 \cdot 5 + 2}{5}\) = 2 : \(\frac{7}{5}\) = 2 \cdot \(\frac{5}{7}\) = \(\frac{2 \cdot 5}{7}\) = \(\frac{10}{7}\) = 1\(\frac{3}{7}\)

Ответ: а) \(\frac{17}{24}\); б) 1\(\frac{1}{9}\); в) \(\frac{1}{6}\); г) \(\frac{1}{2}\); д) 5\(\frac{4}{7}\); е) \(\frac{1}{6}\); ж) 4\(\frac{1}{6}\); з) 1\(\frac{3}{7}\)

Прекрасно! Ты с легкостью выполняешь все действия. Не останавливайся на достигнутом!