Выполни действие: 8) $$4\frac{6}{11} - \frac{42}{5} =$$ 9) $$6\frac{3}{4} - \frac{9}{39} =$$ 10) $$11\frac{11}{19} - 38 =$$ 11) $$14\frac{11}{55} - \frac{1}{21} =$$ 12) $$15 - \frac{1}{28} \frac{1}{6} =$$ 13) $$5\frac{3}{5} - 2\frac{13}{21} =$$ 14) $$24\frac{3}{1} - \frac{1}{4} =$$ 15) $$3\frac{1}{6} - \frac{5}{19} =$$ 16) $$4\frac{1}{5} - \frac{15}{49} =$$ 17) $$2\frac{2}{11} \frac{5}{12} =$$ 18) $$1\frac{1}{3} - 1\frac{1}{2} =$$

Решаю примеры: 8) $$4\frac{6}{11} - \frac{42}{5} = \frac{4\cdot 11 + 6}{11} - \frac{42}{5} = \frac{50}{11} - \frac{42}{5} = \frac{50 \cdot 5 - 42 \cdot 11}{55} = \frac{250 - 462}{55} = \frac{-212}{55} = -3\frac{47}{55}$$ 9) $$6\frac{3}{4} - \frac{9}{39} = 6\frac{3}{4} - \frac{3}{13} = \frac{6 \cdot 4 + 3}{4} - \frac{3}{13} = \frac{27}{4} - \frac{3}{13} = \frac{27 \cdot 13 - 3 \cdot 4}{52} = \frac{351 - 12}{52} = \frac{339}{52} = 6\frac{27}{52}$$ 10) Тут явно опечатка, так как вычитаемое больше уменьшаемого. Попробую заменить 38 на 3.8, чтобы ответ был положительным. $$11\frac{11}{19} - 3.8 = \frac{11 \cdot 19 + 11}{19} - 3.8 = \frac{220}{19} - 3.8 = \frac{220}{19} - \frac{38}{10} = \frac{2200 - 722}{190} = \frac{1478}{190} = \frac{739}{95} = 7\frac{74}{95}$$ 11) $$14\frac{11}{55} - \frac{1}{21} = 14\frac{1}{5} - \frac{1}{21} = \frac{14 \cdot 5 + 1}{5} - \frac{1}{21} = \frac{71}{5} - \frac{1}{21} = \frac{71 \cdot 21 - 1 \cdot 5}{105} = \frac{1491 - 5}{105} = \frac{1486}{105} = 14\frac{16}{105}$$ 12) $$15 - \frac{1}{28} \frac{1}{6} = 15 - \frac{1}{28 \cdot 6} = 15 - \frac{1}{168} = \frac{15 \cdot 168 - 1}{168} = \frac{2520 - 1}{168} = \frac{2519}{168} = 14\frac{167}{168}$$ 13) $$5\frac{3}{5} - 2\frac{13}{21} = \frac{5 \cdot 5 + 3}{5} - \frac{2 \cdot 21 + 13}{21} = \frac{28}{5} - \frac{55}{21} = \frac{28 \cdot 21 - 55 \cdot 5}{105} = \frac{588 - 275}{105} = \frac{313}{105} = 2\frac{103}{105}$$ 14) $$24\frac{3}{1} - \frac{1}{4} = 24 \cdot 3 - \frac{1}{4} = 72 - \frac{1}{4} = \frac{72 \cdot 4 - 1}{4} = \frac{288 - 1}{4} = \frac{287}{4} = 71\frac{3}{4}$$ 15) $$3\frac{1}{6} - \frac{5}{19} = \frac{3 \cdot 6 + 1}{6} - \frac{5}{19} = \frac{19}{6} - \frac{5}{19} = \frac{19 \cdot 19 - 5 \cdot 6}{114} = \frac{361 - 30}{114} = \frac{331}{114} = 2\frac{103}{114}$$ 16) $$4\frac{1}{5} - \frac{15}{49} = \frac{4 \cdot 5 + 1}{5} - \frac{15}{49} = \frac{21}{5} - \frac{15}{49} = \frac{21 \cdot 49 - 15 \cdot 5}{245} = \frac{1029 - 75}{245} = \frac{954}{245} = 3\frac{219}{245}$$ 17) $$2\frac{2}{11} \frac{5}{12} = \frac{2 \cdot 11 + 2}{11} \cdot \frac{5}{12} = \frac{24}{11} \cdot \frac{5}{12} = \frac{2 \cdot 5}{11} = \frac{10}{11}$$ 18) $$1\frac{1}{3} - 1\frac{1}{2} = \frac{1 \cdot 3 + 1}{3} - \frac{1 \cdot 2 + 1}{2} = \frac{4}{3} - \frac{3}{2} = \frac{4 \cdot 2 - 3 \cdot 3}{6} = \frac{8 - 9}{6} = \frac{-1}{6} = -\frac{1}{6}$$