1. Выполните действия: 1) 7 +19; 3)3+47; 16 16' CR 2)+9; 4) 128-8 13' 5) 517 21 8 21 + 6) 148+51-67. 10 10 10

Решим примеры на сложение, вычитание смешанных чисел.

1. $$7 + \frac{8}{19} = \frac{7 \cdot 19}{19} + \frac{8}{19} = \frac{133}{19} + \frac{8}{19} = \frac{133+8}{19} = \frac{141}{19} = 7\frac{8}{19}$$
2. $$\frac{8}{68} + 9 = 9 + \frac{8}{68} = 9\frac{8}{68} = 9\frac{2}{17}$$
3. $$3\frac{5}{16} + 4\frac{7}{16} = (3+4) + (\frac{5}{16} + \frac{7}{16}) = 7 + \frac{5+7}{16} = 7 + \frac{12}{16} = 7 + \frac{3}{4} = 7\frac{3}{4}$$
4. $$12\frac{8}{13} - 8\frac{4}{13} = (12-8) + (\frac{8}{13} - \frac{4}{13}) = 4 + \frac{8-4}{13} = 4 + \frac{4}{13} = 4\frac{4}{13}$$
5. $$5\frac{17}{21} - 3\frac{8}{21} + 4\frac{7}{21} = (5-3+4) + (\frac{17}{21} - \frac{8}{21} + \frac{7}{21}) = 6 + \frac{17-8+7}{21} = 6 + \frac{16}{21} = 6\frac{16}{21}$$
6. $$14\frac{8}{10} + 5\frac{1}{10} - 6\frac{7}{10} = (14+5-6) + (\frac{8}{10} + \frac{1}{10} - \frac{7}{10}) = 13 + \frac{8+1-7}{10} = 13 + \frac{2}{10} = 13 + \frac{1}{5} = 13\frac{1}{5}$$

Ответ: 1) $$7\frac{8}{19}$$; 2) $$9\frac{2}{17}$$; 3) $$7\frac{3}{4}$$; 4) $$4\frac{4}{13}$$; 5) $$6\frac{16}{21}$$; 6) $$13\frac{1}{5}$$