Выполните умножение: 1) 93.10 5 21 : 2) 311.9; 12 94 5 1 3) 1-6; 7 5 4)3.5 9 8 1 4 1352 5) 1 ·2: 15 8 7 6)21.16.41 4 27 3

Выполним умножение смешанных чисел.

1. $$9\frac{3}{5} \cdot \frac{10}{21} = \frac{9 \cdot 5 + 3}{5} \cdot \frac{10}{21} = \frac{45+3}{5} \cdot \frac{10}{21} = \frac{48}{5} \cdot \frac{10}{21} = \frac{48 \cdot 10}{5 \cdot 21} = \frac{48 \cdot 2}{1 \cdot 21} = \frac{96}{21} = \frac{32}{7} = 4\frac{4}{7}$$
2. $$3\frac{11}{12} \cdot \frac{9}{94} = \frac{3 \cdot 12 + 11}{12} \cdot \frac{9}{94} = \frac{36+11}{12} \cdot \frac{9}{94} = \frac{47}{12} \cdot \frac{9}{94} = \frac{47 \cdot 9}{12 \cdot 94} = \frac{1 \cdot 3}{4 \cdot 2} = \frac{3}{8}$$
3. $$1\frac{5}{7} \cdot 6\frac{1}{8} = \frac{1 \cdot 7 + 5}{7} \cdot \frac{6 \cdot 8 + 1}{8} = \frac{7+5}{7} \cdot \frac{48+1}{8} = \frac{12}{7} \cdot \frac{49}{8} = \frac{12 \cdot 49}{7 \cdot 8} = \frac{3 \cdot 7}{1 \cdot 2} = \frac{21}{2} = 10\frac{1}{2}$$
4. $$3\frac{5}{9} \cdot 5\frac{1}{4} = \frac{3 \cdot 9 + 5}{9} \cdot \frac{5 \cdot 4 + 1}{4} = \frac{27+5}{9} \cdot \frac{20+1}{4} = \frac{32}{9} \cdot \frac{21}{4} = \frac{32 \cdot 21}{9 \cdot 4} = \frac{8 \cdot 7}{3 \cdot 1} = \frac{56}{3} = 18\frac{2}{3}$$
5. $$1\frac{13}{15} \cdot \frac{5}{8} \cdot 2\frac{2}{7} = \frac{1 \cdot 15 + 13}{15} \cdot \frac{5}{8} \cdot \frac{2 \cdot 7 + 2}{7} = \frac{15+13}{15} \cdot \frac{5}{8} \cdot \frac{14+2}{7} = \frac{28}{15} \cdot \frac{5}{8} \cdot \frac{16}{7} = \frac{28 \cdot 5 \cdot 16}{15 \cdot 8 \cdot 7} = \frac{4 \cdot 1 \cdot 2}{3 \cdot 1 \cdot 1} = \frac{8}{3} = 2\frac{2}{3}$$
6. $$2\frac{1}{4} \cdot \frac{16}{27} \cdot 4\frac{1}{3} = \frac{2 \cdot 4 + 1}{4} \cdot \frac{16}{27} \cdot \frac{4 \cdot 3 + 1}{3} = \frac{8+1}{4} \cdot \frac{16}{27} \cdot \frac{12+1}{3} = \frac{9}{4} \cdot \frac{16}{27} \cdot \frac{13}{3} = \frac{9 \cdot 16 \cdot 13}{4 \cdot 27 \cdot 3} = \frac{1 \cdot 4 \cdot 13}{1 \cdot 3 \cdot 3} = \frac{52}{9} = 5\frac{7}{9}$$

Ответ:

1. $$4\frac{4}{7}$$
2. $$\frac{3}{8}$$
3. $$10\frac{1}{2}$$
4. $$18\frac{2}{3}$$
5. $$2\frac{2}{3}$$
6. $$5\frac{7}{9}$$