1. Вычислите: 1) $$-3\frac{1}{8} - 16$$ 2) $$-2,84 - 5,49$$ 3) $$-2\frac{4}{15} : (-1,7)$$ 4) $$3\frac{3}{4} - 5\frac{5}{6}$$

1) $$-3\frac{1}{8} - 16 = -3\frac{1}{8} + (-16) = -3\frac{1}{8} - \frac{16 \cdot 8}{8} = -3\frac{1}{8} - \frac{128}{8} = -3\frac{1}{8} - 16 = -19\frac{1}{8} = -\frac{19 \cdot 8 + 1}{8} = -\frac{152 + 1}{8} = -\frac{153}{8} = -19,125$$

2) $$-2,84 - 5,49 = -2,84 + (-5,49) = -8,33$$

3) $$-2\frac{4}{15} : (-1,7) = -\frac{34}{15} : (-1,7) = -\frac{34}{15} : (-\frac{17}{10}) = \frac{34}{15} \cdot \frac{10}{17} = \frac{2 \cdot 17 \cdot 2 \cdot 5}{3 \cdot 5 \cdot 17} = \frac{4}{3} = 1\frac{1}{3}$$

4) $$3\frac{3}{4} - 5\frac{5}{6} = \frac{15}{4} - \frac{35}{6} = \frac{15 \cdot 3}{4 \cdot 3} - \frac{35 \cdot 2}{6 \cdot 2} = \frac{45}{12} - \frac{70}{12} = \frac{45 - 70}{12} = \frac{-25}{12} = -2\frac{1}{12}$$

Ответ:

1. $$-\frac{153}{8} = -19,125$$


2. $$-8,33$$


3. $$1\frac{1}{3}$$


4. $$-2\frac{1}{12}$$