Ответ:

  1. а) \(\frac{5}{9}+\frac{11}{27}=\frac{15}{27}+\frac{11}{27}=\frac{26}{27}\);
    б) \(\frac{2}{3}-\frac{3}{5}=\frac{10}{15}-\frac{9}{15}=\frac{1}{15}\);
    в) \(7-3\frac{2}{4}=7-3\frac{1}{2}=3\frac{1}{2}\);
    г) \(4\frac{5}{6}+8\frac{4}{15}=12+\frac{25}{30}+\frac{8}{30}=12\frac{33}{30}=13\frac{1}{10}\);
    д) \(1\frac{7}{12}-\frac{5}{18}=1+\frac{21}{36}-\frac{10}{36}=1\frac{11}{36}\);
    е) \(2\frac{1}{8}-1\frac{9}{20}=1+\frac{5}{40}-\frac{18}{40}=\frac{27}{40}\).

Ответ: а) \(\frac{26}{27}\); б) \(\frac{1}{15}\); в) \(3\frac{1}{2}\); г) \(13\frac{1}{10}\); д) \(1\frac{11}{36}\); е) \(\frac{27}{40}\).