1. Вычислите: а) \(\frac{39,78-(-5,58)}{-36-\frac{45}{100}}\) б) \(\frac{5}{6}:(-\frac{7}{12})-2\frac{1}{3} \cdot (-\frac{5}{7})\)

Решение:

а) \(\frac{39,78-(-5,58)}{-36-\frac{45}{100}} = \frac{39,78+5,58}{-36-0,45} = \frac{45,36}{-36,45} = -1,2444\) б) \(\frac{5}{6}:(-\frac{7}{12})-2\frac{1}{3} \cdot (-\frac{5}{7}) = \frac{5}{6} \cdot (-\frac{12}{7}) - \frac{7}{3} \cdot (-\frac{5}{7}) = -\frac{10}{7} + \frac{5}{3} = \frac{-30 + 35}{21} = \frac{5}{21}\)

Ответ: a) -1,2444; б) \(\frac{5}{21}\)