ВАРИАНТ 3 1. Выполните умножение: 1) $$\frac{6}{7} \cdot \frac{3}{5}$$; 2) $$\frac{9}{32} \cdot \frac{16}{81}$$; 3) $$\frac{8}{19} \cdot \frac{19}{72}$$; 4) $$\frac{44}{65} \cdot \frac{25}{77}$$. 2. Вычислите: 1) $$4 \cdot \frac{5}{21}$$; 2) $$24 \cdot \frac{7}{12}$$; 3) $$\frac{16}{63} \cdot 9$$; 4) $$36 \cdot \frac{13}{48}$$. 3. Найдите произведение: 1) $$6 \frac{6}{7} \cdot \frac{3}{8}$$; 2) $$5 \frac{1}{7} \cdot 1 \frac{8}{27}$$; 3) $$2 \frac{5}{8} \cdot 2 \frac{2}{7}$$; 4) $$1 \frac{8}{9} \cdot 1 \frac{1}{8} \cdot 2 \frac{2}{3}$$.

1. Выполните умножение:

1) $$rac{6}{7} \cdot \frac{3}{5} = \frac{6 \cdot 3}{7 \cdot 5} = \frac{18}{35}$$

2) $$rac{9}{32} \cdot \frac{16}{81} = \frac{9 \cdot 16}{32 \cdot 81} = \frac{1 \cdot 1}{2 \cdot 9} = \frac{1}{18}$$

3) $$\frac{8}{19} \cdot \frac{19}{72} = \frac{8 \cdot 19}{19 \cdot 72} = \frac{8}{72} = \frac{1}{9}$$

4) $$\frac{44}{65} \cdot \frac{25}{77} = \frac{44 \cdot 25}{65 \cdot 77} = \frac{4 \cdot 5}{13 \cdot 7} = \frac{20}{91}$$

2. Вычислите:

1) $$4 \cdot \frac{5}{21} = \frac{4 \cdot 5}{21} = \frac{20}{21}$$

2) $$24 \cdot \frac{7}{12} = \frac{24 \cdot 7}{12} = \frac{2 \cdot 7}{1} = 14$$

3) $$\frac{16}{63} \cdot 9 = \frac{16 \cdot 9}{63} = \frac{16 \cdot 1}{7} = \frac{16}{7} = 2 \frac{2}{7}$$

4) $$36 \cdot \frac{13}{48} = \frac{36 \cdot 13}{48} = \frac{3 \cdot 13}{4} = \frac{39}{4} = 9 \frac{3}{4}$$

3. Найдите произведение:

1) $$6 \frac{6}{7} \cdot \frac{3}{8} = \frac{6 \cdot 7 + 6}{7} \cdot \frac{3}{8} = \frac{48}{7} \cdot \frac{3}{8} = \frac{6}{7} \cdot \frac{3}{1} = \frac{18}{7} = 2 \frac{4}{7}$$

2) $$5 \frac{1}{7} \cdot 1 \frac{8}{27} = \frac{5 \cdot 7 + 1}{7} \cdot \frac{1 \cdot 27 + 8}{27} = \frac{36}{7} \cdot \frac{35}{27} = \frac{4}{1} \cdot \frac{5}{3} = \frac{20}{3} = 6 \frac{2}{3}$$

3) $$2 \frac{5}{8} \cdot 2 \frac{2}{7} = \frac{2 \cdot 8 + 5}{8} \cdot \frac{2 \cdot 7 + 2}{7} = \frac{21}{8} \cdot \frac{16}{7} = \frac{3}{1} \cdot \frac{2}{1} = 6$$

4) $$1 \frac{8}{9} \cdot 1 \frac{1}{8} \cdot 2 \frac{2}{3} = \frac{1 \cdot 9 + 8}{9} \cdot \frac{1 \cdot 8 + 1}{8} \cdot \frac{2 \cdot 3 + 2}{3} = \frac{17}{9} \cdot \frac{9}{8} \cdot \frac{8}{3} = \frac{17}{1} \cdot \frac{1}{1} \cdot \frac{1}{3} = \frac{17}{3} = 5 \frac{2}{3}$$