17. Тип 2.1 № 1961 Вычислите: 16 21 : 12 35 -2.

Решение:

1. \[ \frac{16}{21} : \frac{12}{35} = \frac{16}{21} \times \frac{35}{12} = \frac{16 \times 35}{21 \times 12} = \frac{4 \times 4 \times 5 \times 7}{3 \times 7 \times 3 \times 4} = \frac{4 \times 5}{3 \times 3} = \frac{20}{9} \]
2. \[ \frac{20}{9} - 2 = \frac{20}{9} - \frac{2 \times 9}{9} = \frac{20 - 18}{9} = \frac{2}{9} \]

Ответ: 2/9