1) Выполни действия: а) 5/9 + 11/27; б) 2/3 − 3/5; в) 7 − 3 3/4; г) 4 5/6 + 8 4/15; д) 1 7/12 − 5/18; е) 2 1/8 − 1 9/20.

1. \(\frac{5}{9}+\frac{11}{27}=\frac{15}{27}+\frac{11}{27}=\frac{26}{27}\).
2. \(\frac{2}{3}-\frac{3}{5}=\frac{10}{15}-\frac{9}{15}=\frac{1}{15}\).
3. \(7-3\frac{3}{4}=7-\frac{15}{4}=\frac{28-15}{4}=\frac{13}{4}=3\frac{1}{4}\).
4. \(4\frac{5}{6}+8\frac{4}{15}=12+\frac{25}{30}+\frac{8}{30}=12\frac{33}{30}=13\frac{1}{10}\).
5. \(1\frac{7}{12}-\frac{5}{18}=1+\frac{21}{36}-\frac{10}{36}=1\frac{11}{36}\).
6. \(2\frac{1}{8}-1\frac{9}{20}=1+\frac{5}{40}-\frac{18}{40}=\frac{27}{40}\).

Ответ: а) \(\frac{26}{27}\); б) \(\frac{1}{15}\); в) \(3\frac{1}{4}\); г) \(13\frac{1}{10}\); д) \(1\frac{11}{36}\); е) \(\frac{27}{40}\).