3.Найдите значение выражений. a)1\frac{1}{9}-\frac{2}{3}; б)12\frac{3}{8}-6\frac{7}{20}; в)4\frac{5}{21}+5\frac{3}{14}; д)\frac{3}{10}:\frac{20}{21}; e)9\frac{1}{3}\cdot1\frac{1}{8}; ж)\frac{9}{14}:\frac{18}{35}; з)3\frac{1}{5}:2\frac{2}{15}.

Ответ: a) \(\frac{4}{9}\); б) \(5\frac{29}{40}\); в) \(9\frac{19}{42}\); д) \(\frac{63}{200}\); e) \(11\frac{1}{4}\); ж) \(1\frac{1}{4}\); з) \(1\frac{1}{2}\)

а) \(1\frac{1}{9}-\frac{2}{3} = \frac{10}{9} - \frac{2}{3} = \frac{10}{9} - \frac{6}{9} = \frac{4}{9}\)

б) \(12\frac{3}{8}-6\frac{7}{20} = 12\frac{15}{40} - 6\frac{14}{40} = 6\frac{1}{40} = 5\frac{41}{40} - 6\frac{14}{40} = 5\frac{27}{40}\)

в) \(4\frac{5}{21}+5\frac{3}{14} = 4\frac{10}{42} + 5\frac{9}{42} = 9\frac{19}{42}\)

д) \(\frac{3}{10}:\frac{20}{21} = \frac{3}{10} \cdot \frac{21}{20} = \frac{63}{200}\)

е) \(9\frac{1}{3}\cdot1\frac{1}{8} = \frac{28}{3} \cdot \frac{9}{8} = \frac{28 \cdot 9}{3 \cdot 8} = \frac{7 \cdot 3}{2} = \frac{21}{2} = 10\frac{1}{2}\)

ж) \(\frac{9}{14}:\frac{18}{35} = \frac{9}{14} \cdot \frac{35}{18} = \frac{9 \cdot 35}{14 \cdot 18} = \frac{1 \cdot 5}{2 \cdot 2} = \frac{5}{4} = 1\frac{1}{4}\)

з) \(3\frac{1}{5}:2\frac{2}{15} = \frac{16}{5} : \frac{32}{15} = \frac{16}{5} \cdot \frac{15}{32} = \frac{16 \cdot 15}{5 \cdot 32} = \frac{1 \cdot 3}{1 \cdot 2} = \frac{3}{2} = 1\frac{1}{2}\)

Ответ: a) \(\frac{4}{9}\); б) \(5\frac{29}{40}\); в) \(9\frac{19}{42}\); д) \(\frac{63}{200}\); e) \(11\frac{1}{4}\); ж) \(1\frac{1}{4}\); з) \(1\frac{1}{2}\)