Выполни умножение: 9 3/5 * 10/21

338. Выполни умножение: 1) $9\frac{3}{5} \cdot \frac{10}{21} = \frac{48}{5} \cdot \frac{10}{21} = \frac{48 \cdot 10}{5 \cdot 21} = \frac{48 \cdot 2}{1 \cdot 21} = \frac{96}{21} = \frac{32}{7} = 4\frac{4}{7}$ 2) $3\frac{11}{12} \cdot \frac{9}{94} = \frac{47}{12} \cdot \frac{9}{94} = \frac{47 \cdot 9}{12 \cdot 94} = \frac{1 \cdot 3}{4 \cdot 2} = \frac{3}{8}$ 3) $1\frac{5}{7} \cdot 6\frac{1}{8} = \frac{12}{7} \cdot \frac{49}{8} = \frac{12 \cdot 49}{7 \cdot 8} = \frac{3 \cdot 7}{1 \cdot 2} = \frac{21}{2} = 10\frac{1}{2}$ 4) $3\frac{5}{9} \cdot 5\frac{1}{4} = \frac{32}{9} \cdot \frac{21}{4} = \frac{32 \cdot 21}{9 \cdot 4} = \frac{8 \cdot 7}{3 \cdot 1} = \frac{56}{3} = 18\frac{2}{3}$ 5) $1\frac{13}{15} \cdot \frac{5}{8} \cdot 2\frac{2}{7} = \frac{28}{15} \cdot \frac{5}{8} \cdot \frac{16}{7} = \frac{28 \cdot 5 \cdot 16}{15 \cdot 8 \cdot 7} = \frac{4 \cdot 1 \cdot 2}{3 \cdot 1 \cdot 1} = \frac{8}{3} = 2\frac{2}{3}$ 6) $2\frac{1}{4} \cdot \frac{16}{27} \cdot 4\frac{1}{3} = \frac{9}{4} \cdot \frac{16}{27} \cdot \frac{13}{3} = \frac{9 \cdot 16 \cdot 13}{4 \cdot 27 \cdot 3} = \frac{1 \cdot 4 \cdot 13}{1 \cdot 3 \cdot 3} = \frac{52}{9} = 5\frac{7}{9}$ 339. Найдите произведение: 1) $0.4 \cdot \frac{5}{9} = \frac{4}{10} \cdot \frac{5}{9} = \frac{2}{5} \cdot \frac{5}{9} = \frac{2 \cdot 5}{5 \cdot 9} = \frac{2}{9}$ 2) $\frac{8}{27} \cdot 0.75 = \frac{8}{27} \cdot \frac{75}{100} = \frac{8}{27} \cdot \frac{3}{4} = \frac{8 \cdot 3}{27 \cdot 4} = \frac{2 \cdot 1}{9 \cdot 1} = \frac{2}{9}$ 3) $1.5 \cdot \frac{1}{6} = \frac{15}{10} \cdot \frac{1}{6} = \frac{3}{2} \cdot \frac{1}{6} = \frac{3 \cdot 1}{2 \cdot 6} = \frac{1 \cdot 1}{2 \cdot 2} = \frac{1}{4}$ 4) $2\frac{1}{7} \cdot 2.8 = \frac{15}{7} \cdot \frac{28}{10} = \frac{15 \cdot 28}{7 \cdot 10} = \frac{3 \cdot 4}{1 \cdot 2} = \frac{12}{2} = 6$ 340. Выполните умножение: 1) $0.8 \cdot \frac{7}{12} = \frac{8}{10} \cdot \frac{7}{12} = \frac{4}{5} \cdot \frac{7}{12} = \frac{4 \cdot 7}{5 \cdot 12} = \frac{1 \cdot 7}{5 \cdot 3} = \frac{7}{15}$ 2) $1\frac{2}{3} \cdot 0.6 = \frac{5}{3} \cdot \frac{6}{10} = \frac{5 \cdot 6}{3 \cdot 10} = \frac{1 \cdot 2}{1 \cdot 2} = 1$ 3) $1.25 \cdot \frac{32}{45} = \frac{125}{100} \cdot \frac{32}{45} = \frac{5}{4} \cdot \frac{32}{45} = \frac{5 \cdot 32}{4 \cdot 45} = \frac{1 \cdot 8}{1 \cdot 9} = \frac{8}{9}$ 4) $4.5 \cdot 3\frac{1}{3} = \frac{45}{10} \cdot \frac{10}{3} = \frac{45 \cdot 10}{10 \cdot 3} = \frac{15 \cdot 1}{1 \cdot 1} = 15$ 341. Найдите значение выражения: 1) $(\frac{11}{18} - \frac{4}{9}) \cdot \frac{3}{16} = (\frac{11}{18} - \frac{8}{18}) \cdot \frac{3}{16} = \frac{3}{18} \cdot \frac{3}{16} = \frac{3 \cdot 3}{18 \cdot 16} = \frac{1 \cdot 1}{2 \cdot 16} = \frac{1}{32}$ 2) $\frac{11}{18} - \frac{4}{9} \cdot \frac{3}{16} = \frac{11}{18} - \frac{4 \cdot 3}{9 \cdot 16} = \frac{11}{18} - \frac{1 \cdot 1}{3 \cdot 4} = \frac{11}{18} - \frac{1}{12} = \frac{22}{36} - \frac{3}{36} = \frac{19}{36}$ 3) $1\frac{3}{5} \cdot (\frac{3}{4} + 1\frac{3}{8}) = \frac{8}{5} \cdot (\frac{3}{4} + \frac{11}{8}) = \frac{8}{5} \cdot (\frac{6}{8} + \frac{11}{8}) = \frac{8}{5} \cdot \frac{17}{8} = \frac{8 \cdot 17}{5 \cdot 8} = \frac{17}{5} = 3\frac{2}{5}$ 4) $1\frac{3}{5} \cdot \frac{3}{4} + 1\frac{3}{8} = \frac{8}{5} \cdot \frac{3}{4} + \frac{11}{8} = \frac{8 \cdot 3}{5 \cdot 4} + \frac{11}{8} = \frac{2 \cdot 3}{5 \cdot 1} + \frac{11}{8} = \frac{6}{5} + \frac{11}{8} = \frac{48}{40} + \frac{55}{40} = \frac{103}{40} = 2\frac{23}{40}$ 5) $13\frac{4}{5} - 3\frac{1}{3} \cdot 3\frac{3}{4} = \frac{69}{5} - \frac{10}{3} \cdot \frac{15}{4} = \frac{69}{5} - \frac{10 \cdot 15}{3 \cdot 4} = \frac{69}{5} - \frac{5 \cdot 5}{1 \cdot 2} = \frac{69}{5} - \frac{25}{2} = \frac{138}{10} - \frac{125}{10} = \frac{13}{10} = 1\frac{3}{10}$