1) 6\frac{4}{9}+3\frac{5}{9}; 2) 10\frac{11}{19}+5\frac{14}{19}; 3) 2\frac{3}{13}+2\frac{11}{13}; 4) 1\frac{5}{8}+3\frac{3}{8}; 5) 1-\frac{3}{11}; 6) 1-\frac{13}{40}; 7) 4-1\frac{4}{7}; 8) 10-9\frac{3}{10}; 9) 5\frac{2}{7}-2\frac{5}{7}; 10) 14\frac{6}{20}-8\frac{12}{20}; 11) 8\frac{3}{14}-5\frac{9}{14}; 12) 7\frac{10}{21}-4\frac{16}{21}; 13) 14\frac{8}{31}-6\frac{31}{31}; 14) (12\frac{5}{22}+7\frac{17}{22})

Решим примеры по порядку:

1) \(6\frac{4}{9}+3\frac{5}{9} = (6+3) + (\frac{4}{9} + \frac{5}{9}) = 9 + \frac{9}{9} = 9 + 1 = 10\) 2) \(10\frac{11}{19}+5\frac{14}{19} = (10+5) + (\frac{11}{19} + \frac{14}{19}) = 15 + \frac{25}{19} = 15 + 1\frac{6}{19} = 16\frac{6}{19}\) 3) \(2\frac{3}{13}+2\frac{11}{13} = (2+2) + (\frac{3}{13} + \frac{11}{13}) = 4 + \frac{14}{13} = 4 + 1\frac{1}{13} = 5\frac{1}{13}\) 4) \(1\frac{5}{8}+3\frac{3}{8} = (1+3) + (\frac{5}{8} + \frac{3}{8}) = 4 + \frac{8}{8} = 4 + 1 = 5\) 5) \(1-\frac{3}{11} = \frac{11}{11} - \frac{3}{11} = \frac{8}{11}\) 6) \(1-\frac{13}{40} = \frac{40}{40} - \frac{13}{40} = \frac{27}{40}\) 7) \(4-1\frac{4}{7} = 3\frac{7}{7} - 1\frac{4}{7} = (3-1) + (\frac{7}{7} - \frac{4}{7}) = 2 + \frac{3}{7} = 2\frac{3}{7}\) 8) \(10-9\frac{3}{10} = 9\frac{10}{10} - 9\frac{3}{10} = (9-9) + (\frac{10}{10} - \frac{3}{10}) = 0 + \frac{7}{10} = \frac{7}{10}\) 9) \(5\frac{2}{7}-2\frac{5}{7} = 4\frac{9}{7}-2\frac{5}{7} = (4-2) + (\frac{9}{7} - \frac{5}{7}) = 2 + \frac{4}{7} = 2\frac{4}{7}\) 10) \(14\frac{6}{20}-8\frac{12}{20} = 13\frac{26}{20}-8\frac{12}{20} = (13-8) + (\frac{26}{20} - \frac{12}{20}) = 5 + \frac{14}{20} = 5\frac{7}{10}\) 11) \(8\frac{3}{14}-5\frac{9}{14} = 7\frac{17}{14}-5\frac{9}{14} = (7-5) + (\frac{17}{14} - \frac{9}{14}) = 2 + \frac{8}{14} = 2\frac{4}{7}\) 12) \(7\frac{10}{21}-4\frac{16}{21} = 6\frac{31}{21}-4\frac{16}{21} = (6-4) + (\frac{31}{21} - \frac{16}{21}) = 2 + \frac{15}{21} = 2\frac{5}{7}\) 13) \(14\frac{8}{31}-6\frac{31}{31} = 13\frac{39}{31}-6\frac{31}{31} = (13-6) + (\frac{39}{31} - \frac{31}{31}) = 7 + \frac{8}{31} = 7\frac{8}{31}\) 14) \((12\frac{5}{22}+7\frac{17}{22}) = (12+7) + (\frac{5}{22} + \frac{17}{22}) = 19 + \frac{22}{22} = 19 + 1 = 20\)

Ответ: 1) 10; 2) \(16\frac{6}{19}\); 3) \(5\frac{1}{13}\); 4) 5; 5) \(\frac{8}{11}\); 6) \(\frac{27}{40}\); 7) \(2\frac{3}{7}\); 8) \(\frac{7}{10}\); 9) \(2\frac{4}{7}\); 10) \(5\frac{7}{10}\); 11) \(2\frac{4}{7}\); 12) \(2\frac{5}{7}\); 13) \(7\frac{8}{31}\); 14) 20

Прекрасно! Ты отлично справился с этими примерами. Продолжай в том же духе, и у тебя всё получится! Молодец!