Вопрос:

1. Вычислите: а) \((1\frac{1}{3}-2\frac{5}{6}):(0,75-1\frac{1}{6})\); б) \((1,2-1\frac{7}{15})\cdot(-\frac{5}{8})-1\frac{1}{6}:2\frac{1}{3}\).

Ответ:

а)

\(1\frac{1}{3}=\frac{4}{3}\), \(2\frac{5}{6}=\frac{17}{6}\), \(0,75=\frac{3}{4}\).

\(\left(\frac{4}{3}-\frac{17}{6}\right):\left(\frac{3}{4}-\frac{7}{6}\right)=\left(-\frac{3}{2}\right):\left(-\frac{5}{12}\right)=\frac{18}{5}=3\frac{3}{5}.\)

б)

\(1,2=\frac{6}{5}\), поэтому

\(\left(\frac{6}{5}-\frac{22}{15}\right)\cdot\left(-\frac{5}{8}\right)-\frac{7}{6}:\frac{7}{3}=\left(-\frac{4}{15}\right)\cdot\left(-\frac{5}{8}\right)-\frac{1}{2}=\frac{1}{6}-\frac{1}{2}=-\frac{1}{3}.\)

Ответ: а) \(3\frac{3}{5}\); б) \(-\frac{1}{3}\).