B-1, 2. Вычислить: 3 : 3\frac{3}{4} + 2\frac{1}{5} \cdot 2 - 3\frac{5}{6}

Решение: 1. \(3\frac{3}{4} = \frac{3 \cdot 4 + 3}{4} = \frac{15}{4}\) 2. \(2\frac{1}{5} = \frac{2 \cdot 5 + 1}{5} = \frac{11}{5}\) 3. \(3\frac{5}{6} = \frac{3 \cdot 6 + 5}{6} = \frac{23}{6}\) 4. \(3 : \frac{15}{4} = 3 \cdot \frac{4}{15} = \frac{12}{15} = \frac{4}{5}\) 5. \(\frac{11}{5} \cdot 2 = \frac{11 \cdot 2}{5} = \frac{22}{5}\) 6. \(\frac{4}{5} + \frac{22}{5} - \frac{23}{6} = \frac{26}{5} - \frac{23}{6} = \frac{26 \cdot 6 - 23 \cdot 5}{30} = \frac{156 - 115}{30} = \frac{41}{30} = 1\frac{11}{30}\) Ответ: \(1\frac{11}{30}\)