Найдите значение выражения: a) $$1\frac{5}{17} \cdot (7 - 2\frac{4}{11})$$ б) $$(4,2 : 1,2 - 1,05) \cdot 1,6$$

1. а) $$1\frac{5}{17} \cdot (7 - 2\frac{4}{11}) = \frac{22}{17} \cdot (\frac{77}{11} - \frac{26}{11}) = \frac{22}{17} \cdot \frac{51}{11} = \frac{22 \cdot 51}{17 \cdot 11} = \frac{2 \cdot 3}{1 \cdot 1} = 6$$

2. б) $$(4,2 : 1,2 - 1,05) \cdot 1,6 = (4,2 : 1,2 - 1,05) \cdot 1,6 = (\frac{42}{10} : \frac{12}{10} - \frac{105}{100}) \cdot \frac{16}{10} = (\frac{42}{10} \cdot \frac{10}{12} - \frac{105}{100}) \cdot \frac{16}{10} = (\frac{42}{12} - \frac{105}{100}) \cdot \frac{16}{10} = (\frac{7}{2} - \frac{21}{20}) \cdot \frac{16}{10} = (\frac{70}{20} - \frac{21}{20}) \cdot \frac{16}{10} = \frac{49}{20} \cdot \frac{16}{10} = \frac{49 \cdot 16}{20 \cdot 10} = \frac{49 \cdot 4}{5 \cdot 10} = \frac{196}{50} = \frac{98}{25} = 3\frac{23}{25} = 3,92$$

Ответ:

• а) 6
• б) 3,92