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

Решение:

1. 1) $$-3 \frac{1}{8} \cdot 16 = -\frac{25}{8} \cdot 16 = -25 \cdot 2 = -50$$
2. 2) $$-2,84 - 5,49 = -8,33$$
3. 3) $$2 - (-6) - 8 = 2 + 6 - 8 = 8 - 8 = 0$$
4. 4) $$-2 \frac{4}{15} : (-1,7) = -\frac{34}{15} : (-\frac{17}{10}) = \frac{34}{15} \cdot \frac{10}{17} = \frac{2 \cdot 17}{3 \cdot 5} \cdot \frac{2 \cdot 5}{17} = \frac{2 \cdot 2}{3} = \frac{4}{3} = 1 \frac{1}{3}$$
5. 5) $$3 \frac{3}{4} - 5 \frac{5}{6} = \frac{15}{4} - \frac{35}{6} = \frac{15 \cdot 3}{12} - \frac{35 \cdot 2}{12} = \frac{45 - 70}{12} = -\frac{25}{12} = -2 \frac{1}{12}$$

Ответ: 1) -50; 2) -8,33; 3) 0; 4) $$1 \frac{1}{3}$$; 5) $$-2 \frac{1}{12}$$.