(1 балл) Выполните действия: 1. 4\frac{11}{20}+3\frac{3}{20}; 2. 5\frac{9}{11}+6\frac{10}{11}; 3. 8\frac{1}{23}+7\frac{22}{23}-6\frac{10}{23}; 4. 10\frac{3}{28}-(6\frac{5}{28}+3\frac{6}{28}).

Выполните действия:

1. $$4\frac{11}{20}+3\frac{3}{20} = (4+3) + (\frac{11}{20}+\frac{3}{20}) = 7 + \frac{11+3}{20} = 7 + \frac{14}{20} = 7 + \frac{7}{10} = 7\frac{7}{10}$$
2. $$5\frac{9}{11}+6\frac{10}{11} = (5+6) + (\frac{9}{11}+\frac{10}{11}) = 11 + \frac{9+10}{11} = 11 + \frac{19}{11} = 11 + 1\frac{8}{11} = 12\frac{8}{11}$$
3. $$8\frac{1}{23}+7\frac{22}{23}-6\frac{10}{23} = (8+7-6) + (\frac{1}{23}+\frac{22}{23}-\frac{10}{23}) = 9 + \frac{1+22-10}{23} = 9 + \frac{13}{23} = 9\frac{13}{23}$$
4. $$10\frac{3}{28}-(6\frac{5}{28}+3\frac{6}{28}) = 10\frac{3}{28}-((6+3)+(\frac{5}{28}+\frac{6}{28})) = 10\frac{3}{28}-(9+\frac{5+6}{28}) = 10\frac{3}{28}-(9+\frac{11}{28}) = 10\frac{3}{28}-9\frac{11}{28} = (10-9) + (\frac{3}{28}-\frac{11}{28}) = 1 + \frac{3-11}{28} = 1 + \frac{-8}{28} = 1 - \frac{8}{28} = 1 - \frac{2}{7} = \frac{7}{7} - \frac{2}{7} = \frac{7-2}{7} = \frac{5}{7}$$

Ответ: 1. $$7\frac{7}{10}$$, 2. $$12\frac{8}{11}$$, 3. $$9\frac{13}{23}$$, 4. $$\frac{5}{7}$$