Выполни действия 8) 4642 11 5 9 2 1. 39 ८ 10) 1.38= 1 19 11) 1. 141 55 21 = 15 28 2 13) 52- 21 14) 24.3= 15) 3 = 41.15 16) 45 49 = 17) 2 11 12 18) 1/4-1/2- 19) 33

Давай выполним действия по порядку! 8) \(4 \frac{6}{11} - 2 \frac{4}{5} = \frac{4 \cdot 11 + 6}{11} - \frac{2 \cdot 5 + 4}{5} = \frac{44+6}{11} - \frac{10+4}{5} = \frac{50}{11} - \frac{14}{5} = \frac{50 \cdot 5 - 14 \cdot 11}{11 \cdot 5} = \frac{250 - 154}{55} = \frac{96}{55} = 1 \frac{41}{55}\) 9) \(6 \frac{3}{4} \cdot \frac{1}{39} = \frac{6 \cdot 4 + 3}{4} \cdot \frac{1}{39} = \frac{24 + 3}{4} \cdot \frac{1}{39} = \frac{27}{4} \cdot \frac{1}{39} = \frac{27}{4 \cdot 39} = \frac{9 \cdot 3}{4 \cdot 13 \cdot 3} = \frac{9}{4 \cdot 13} = \frac{9}{52}\) 10) \(\frac{11}{19} \cdot 38 = \frac{11 \cdot 38}{19} = \frac{11 \cdot 2 \cdot 19}{19} = 11 \cdot 2 = 22\) 11) \(14 \frac{1}{55} \cdot \frac{1}{21} = \frac{14 \cdot 55 + 1}{55} \cdot \frac{1}{21} = \frac{770+1}{55} \cdot \frac{1}{21} = \frac{771}{55} \cdot \frac{1}{21} = \frac{771}{55 \cdot 21} = \frac{257 \cdot 3}{55 \cdot 7 \cdot 3} = \frac{257}{385}\) 12) \(\frac{15}{28} \cdot 1 \frac{1}{6} = \frac{15}{28} \cdot \frac{1 \cdot 6 + 1}{6} = \frac{15}{28} \cdot \frac{7}{6} = \frac{15 \cdot 7}{28 \cdot 6} = \frac{5 \cdot 3 \cdot 7}{4 \cdot 7 \cdot 2 \cdot 3} = \frac{5}{4 \cdot 2} = \frac{5}{8}\) 13) \(5 \frac{3}{5} \cdot 2 \frac{13}{21} = \frac{5 \cdot 5 + 3}{5} \cdot \frac{2 \cdot 21 + 13}{21} = \frac{25+3}{5} \cdot \frac{42+13}{21} = \frac{28}{5} \cdot \frac{55}{21} = \frac{28 \cdot 55}{5 \cdot 21} = \frac{4 \cdot 7 \cdot 11 \cdot 5}{5 \cdot 3 \cdot 7} = \frac{4 \cdot 11}{3} = \frac{44}{3} = 14 \frac{2}{3}\) 14) \(24 \cdot 3 \frac{1}{4} = 24 \cdot \frac{3 \cdot 4 + 1}{4} = 24 \cdot \frac{12+1}{4} = 24 \cdot \frac{13}{4} = \frac{24 \cdot 13}{4} = 6 \cdot 13 = 78\) 15) \(3 \frac{1}{6} \cdot \frac{5}{19} = \frac{3 \cdot 6 + 1}{6} \cdot \frac{5}{19} = \frac{18+1}{6} \cdot \frac{5}{19} = \frac{19}{6} \cdot \frac{5}{19} = \frac{19 \cdot 5}{6 \cdot 19} = \frac{5}{6}\) 16) \(4 \frac{1}{45} \cdot \frac{15}{49} = \frac{4 \cdot 45 + 1}{45} \cdot \frac{15}{49} = \frac{180+1}{45} \cdot \frac{15}{49} = \frac{181}{45} \cdot \frac{15}{49} = \frac{181 \cdot 15}{45 \cdot 49} = \frac{181 \cdot 3 \cdot 5}{9 \cdot 5 \cdot 49} = \frac{181 \cdot 3}{9 \cdot 49} = \frac{181}{3 \cdot 49} = \frac{181}{147}\) 17) \(2 \frac{2}{11} \cdot \frac{5}{12} = \frac{2 \cdot 11 + 2}{11} \cdot \frac{5}{12} = \frac{22+2}{11} \cdot \frac{5}{12} = \frac{24}{11} \cdot \frac{5}{12} = \frac{24 \cdot 5}{11 \cdot 12} = \frac{2 \cdot 12 \cdot 5}{11 \cdot 12} = \frac{2 \cdot 5}{11} = \frac{10}{11}\) 18) \(1 \frac{1}{3} - 1 \frac{1}{2} = \frac{1 \cdot 3 + 1}{3} - \frac{1 \cdot 2 + 1}{2} = \frac{4}{3} - \frac{3}{2} = \frac{4 \cdot 2 - 3 \cdot 3}{3 \cdot 2} = \frac{8-9}{6} = -\frac{1}{6}\) 19) \(3 \frac{1}{2} \cdot 3 \frac{1}{2} = \frac{3 \cdot 2 + 1}{2} \cdot \frac{3 \cdot 2 + 1}{2} = \frac{7}{2} \cdot \frac{7}{2} = \frac{49}{4} = 12 \frac{1}{4}\)

Ответ: 8) \(1 \frac{41}{55}\), 9) \(\frac{9}{52}\), 10) \(22\), 11) \(\frac{257}{385}\), 12) \(\frac{5}{8}\), 13) \(14 \frac{2}{3}\), 14) \(78\), 15) \(\frac{5}{6}\), 16) \(\frac{181}{147}\), 17) \(\frac{10}{11}\), 18) \(-\frac{1}{6}\), 19) \(12 \frac{1}{4}\)

Ты молодец! У тебя всё получится! Не бойся трудностей, ведь они делают тебя сильнее и умнее!