Вариант 3. Выполните сложение: а) 4/7 + 5/6; б) 5/12 + 2/15; в) 3/7 + 5/14; г) 5/18 + 7/30; д) 13/25 + 7/10; е) 8/9 + 7/12; ж) 15/19 + 27/37; з) 4/21 + 5/7; и) 0,22 + 3/25 + 1/20.

1. \(\frac{4}{7}+\frac{5}{6}=\frac{24}{42}+\frac{35}{42}=\frac{59}{42}=1\frac{17}{42}\).
2. \(\frac{5}{12}+\frac{2}{15}=\frac{25}{60}+\frac{8}{60}=\frac{33}{60}=\frac{11}{20}\).
3. \(\frac{3}{7}+\frac{5}{14}=\frac{6}{14}+\frac{5}{14}=\frac{11}{14}\).
4. \(\frac{5}{18}+\frac{7}{30}=\frac{25}{90}+\frac{21}{90}=\frac{46}{90}=\frac{23}{45}\).
5. \(\frac{13}{25}+\frac{7}{10}=\frac{26}{50}+\frac{35}{50}=\frac{61}{50}=1\frac{11}{50}\).
6. \(\frac{8}{9}+\frac{7}{12}=\frac{32}{36}+\frac{21}{36}=\frac{53}{36}=1\frac{17}{36}\).
7. \(\frac{15}{19}+\frac{27}{37}=\frac{555}{703}+\frac{513}{703}=\frac{1068}{703}=1\frac{365}{703}\).
8. \(\frac{4}{21}+\frac{5}{7}=\frac{4}{21}+\frac{15}{21}=\frac{19}{21}\).
9. \(0{,}22+\frac{3}{25}+\frac{1}{20}=\frac{22}{100}+\frac{12}{100}+\frac{5}{100}=\frac{39}{100}=0{,}39\).

Ответ: а) \(1\frac{17}{42}\); б) \(\frac{11}{20}\); в) \(\frac{11}{14}\); г) \(\frac{23}{45}\); д) \(1\frac{11}{50}\); е) \(1\frac{17}{36}\); ж) \(1\frac{365}{703}\); з) \(\frac{19}{21}\); и) \(0{,}39\).