Задание 4. Вычисли и результат переведи в смешанное число. 1. 1\frac{7}{9} + \frac{8}{9} 2. 2\frac{12}{15} + \frac{14}{15} 3. 3\frac{51}{17} + \frac{9}{17} 4. 4\frac{12}{21} + \frac{19}{21} 5. 5\frac{19}{25} + \frac{6}{25} 6. 6\frac{14}{21} + \frac{28}{21} 7. 7\frac{29}{10} - \frac{9}{10} 8. 8\frac{19}{35} + \frac{31}{35}

Задание 4. Вычислим и результат переведем в смешанное число.

1. $$1\frac{7}{9} + \frac{8}{9} = 1 + \frac{7+8}{9} = 1 + \frac{15}{9} = 1 + 1\frac{6}{9} = 2\frac{6}{9} = 2\frac{2}{3}$$
2. $$2\frac{12}{15} + \frac{14}{15} = 2 + \frac{12+14}{15} = 2 + \frac{26}{15} = 2 + 1\frac{11}{15} = 3\frac{11}{15}$$
3. $$3\frac{51}{17} + \frac{9}{17} = 3 + \frac{51+9}{17} = 3 + \frac{60}{17} = 3 + 3\frac{9}{17} = 6\frac{9}{17}$$
4. $$4\frac{12}{21} + \frac{19}{21} = 4 + \frac{12+19}{21} = 4 + \frac{31}{21} = 4 + 1\frac{10}{21} = 5\frac{10}{21}$$
5. $$5\frac{19}{25} + \frac{6}{25} = 5 + \frac{19+6}{25} = 5 + \frac{25}{25} = 5 + 1 = 6$$
6. $$6\frac{14}{21} + \frac{28}{21} = 6 + \frac{14+28}{21} = 6 + \frac{42}{21} = 6 + 2 = 8$$
7. $$7\frac{29}{10} - \frac{9}{10} = 7 + \frac{29-9}{10} = 7 + \frac{20}{10} = 7 + 2 = 9$$
8. $$8\frac{19}{35} + \frac{31}{35} = 8 + \frac{19+31}{35} = 8 + \frac{50}{35} = 8 + 1\frac{15}{35} = 9\frac{15}{35} = 9\frac{3}{7}$$

Ответ: 1) $$2\frac{2}{3}$$, 2) $$3\frac{11}{15}$$, 3) $$6\frac{9}{17}$$, 4) $$5\frac{10}{21}$$, 5) $$6$$, 6) $$8$$, 7) $$9$$, 8) $$9\frac{3}{7}$$