Часть 1 1. Вычислить. 1) $$-1 \frac{1}{5} \cdot (-15)$$ 2) $$-1,95 - 8,68$$ 3) $$-7 - (-4) + 3$$ 4) $$-2,16 : \frac{3}{50}$$ 5) $$1 \frac{1}{8} - 3 \frac{5}{6}$$

Решение:

1. $$-1 \frac{1}{5} \cdot (-15) = -\frac{6}{5} \cdot (-15) = \frac{6 \cdot 15}{5} = 6 \cdot 3 = 18$$
2. $$-1,95 - 8,68 = -10,63$$
3. $$-7 - (-4) + 3 = -7 + 4 + 3 = 0$$
4. $$-2,16 : \frac{3}{50} = -2,16 \cdot \frac{50}{3} = -0,72 \cdot 50 = -36$$
5. $$1 \frac{1}{8} - 3 \frac{5}{6} = \frac{9}{8} - \frac{23}{6} = \frac{9 \cdot 3}{24} - \frac{23 \cdot 4}{24} = \frac{27 - 92}{24} = -\frac{65}{24} = -2 \frac{17}{24}$$

Ответ: 1) 18; 2) -10,63; 3) 0; 4) -36; 5) $$-2 \frac{17}{24}$$.