1. Найдите значение выражения: 1) (-1,56 - 1,24) · (-1 1 5/14); 2) (4/9 - 3/12) : (-1 8/27).

Решение:

• 1) \[ (-1.56 - 1.24) \cdot \left(-1 \frac{5}{14}\right) = (-2.8) \cdot \left(-\frac{19}{14}\right) = \frac{28}{10} \cdot \frac{19}{14} = \frac{2 \cdot 14}{10} \cdot \frac{19}{14} = \frac{2 \cdot 19}{10} = \frac{38}{10} = 3.8 \]
• 2) \[ \left(\frac{4}{9} - \frac{3}{12}\right) : \left(-1 \frac{8}{27}\right) = \left(\frac{4}{9} - \frac{1}{4}\right) : \left(-\frac{35}{27}\right) = \left(\frac{16 - 9}{36}\right) : \left(-\frac{35}{27}\right) = \frac{7}{36} : \left(-\frac{35}{27}\right) = \frac{7}{36} \cdot \left(-\frac{27}{35}\right) = \frac{7}{4 \cdot 9} \cdot \left(-\frac{3 \cdot 9}{5 \cdot 7}\right) = \frac{1}{4} \cdot \left(-\frac{3}{5}\right) = -\frac{3}{20} = -0.15 \]

Ответ: 1) 3.8; 2) -0.15.