1. Вычислите: a) • ; 6) 욕·; B) ·음;)(); % ):; e) :: 2. Вычислите: )20:43; 3) 3: a) 2. (0:0); 6) : • : B) ··춤·음 25 2026/04/08 21:46

1. Вычислите:

1. а) \[ \frac{2}{3} \cdot \frac{4}{5} = \frac{2 \cdot 4}{3 \cdot 5} = \frac{8}{15} \]
2. б) \[ \frac{3}{7} \cdot \frac{7}{8} = \frac{3 \cdot 7}{7 \cdot 8} = \frac{3}{8} \]
3. в) \[ \frac{11}{12} \cdot \frac{8}{9} = \frac{11 \cdot 8}{12 \cdot 9} = \frac{22}{27} \]
4. г) \[ (\frac{2}{3})^3 = \frac{2^3}{3^3} = \frac{8}{27} \]
5. д) \[ \frac{2}{3} : \frac{5}{7} = \frac{2}{3} \cdot \frac{7}{5} = \frac{2 \cdot 7}{3 \cdot 5} = \frac{14}{15} \]
6. е) \[ \frac{9}{16} : \frac{3}{2} = \frac{9}{16} \cdot \frac{2}{3} = \frac{9 \cdot 2}{16 \cdot 3} = \frac{3}{8} \]
7. ж) \[ \frac{3}{4} : 4 = \frac{3}{4} : \frac{4}{1} = \frac{3}{4} \cdot \frac{1}{4} = \frac{3 \cdot 1}{4 \cdot 4} = \frac{3}{16} \]
8. з) \[ 3 : \frac{9}{8} = \frac{3}{1} : \frac{9}{8} = \frac{3}{1} \cdot \frac{8}{9} = \frac{3 \cdot 8}{1 \cdot 9} = \frac{8}{3} = 2\frac{2}{3} \]

2. Вычислите:

1. а) \[ 2 \cdot (\frac{12}{25} : \frac{6}{5}) = 2 \cdot (\frac{12}{25} \cdot \frac{5}{6}) = 2 \cdot \frac{12 \cdot 5}{25 \cdot 6} = 2 \cdot \frac{2}{5} = \frac{4}{5} \]
2. б) \[ \frac{14}{15} \cdot \frac{2}{3} \cdot \frac{10}{21} = \frac{14 \cdot 2 \cdot 10}{15 \cdot 3 \cdot 21} = \frac{4 \cdot 2 \cdot 2}{3 \cdot 3 \cdot 3} = \frac{8}{27} \]
3. в) \[ \frac{2}{3} \cdot \frac{3}{4} \cdot \frac{4}{5} \cdot \frac{5}{6} = \frac{2 \cdot 3 \cdot 4 \cdot 5}{3 \cdot 4 \cdot 5 \cdot 6} = \frac{2}{6} = \frac{1}{3} \]