Вариант 2. Выполни действие: 13) 27/28 + 4 9/28 =; 14) 4 7/20 + 2 17/20 =; 15) 23/26 + 11/26 =; 16) 3 10/13 + 5 11/13 =; 17) 8/11 + 5/11 =.

13) \(\frac{27}{28}+4\frac{9}{28}=4\frac{36}{28}=5\frac{8}{28}=5\frac{2}{7}\).

14) \(4\frac{7}{20}+2\frac{17}{20}=6\frac{24}{20}=7\frac{4}{20}=7\frac{1}{5}\).

15) \(\frac{23}{26}+\frac{11}{26}=\frac{34}{26}=\frac{17}{13}=1\frac{4}{13}\).

16) \(3\frac{10}{13}+5\frac{11}{13}=8\frac{21}{13}=9\frac{8}{13}\).

17) \(\frac{8}{11}+\frac{5}{11}=\frac{13}{11}=1\frac{2}{11}\).

Ответ: 13) \(5\frac{2}{7}\); 14) \(7\frac{1}{5}\); 15) \(1\frac{4}{13}\); 16) \(9\frac{8}{13}\); 17) \(1\frac{2}{11}\).