5) 4 1/3 * 5 + 2,4 : (-0,1) - 14/15 : 1 2/5

Давайте решим примеры по действиям. **6) $3\frac{1}{7} \cdot (-4) - 1,8 : (-0,1) + \frac{20}{21} : 1\frac{2}{3}$** 1) $3\frac{1}{7} \cdot (-4) = \frac{22}{7} \cdot (-4) = -\frac{88}{7} = -12\frac{4}{7}$ 2) $1,8 : (-0,1) = -18$ 3) $\frac{20}{21} : 1\frac{2}{3} = \frac{20}{21} : \frac{5}{3} = \frac{20}{21} \cdot \frac{3}{5} = \frac{4}{7}$ 4) $-12\frac{4}{7} - (-18) + \frac{4}{7} = -12\frac{4}{7} + 18 + \frac{4}{7} = -12 + 18 = 6$ **Ответ: 6** **7) $\frac{7}{9} : 1\frac{1}{6} + 2,7 : (-0,1) - 4\frac{1}{3} \cdot (-4)$** 1) $\frac{7}{9} : 1\frac{1}{6} = \frac{7}{9} : \frac{7}{6} = \frac{7}{9} \cdot \frac{6}{7} = \frac{2}{3}$ 2) $2,7 : (-0,1) = -27$ 3) $4\frac{1}{3} \cdot (-4) = \frac{13}{3} \cdot (-4) = -\frac{52}{3} = -17\frac{1}{3}$ 4) $\frac{2}{3} + (-27) - (-17\frac{1}{3}) = \frac{2}{3} - 27 + 17\frac{1}{3} = \frac{3}{3} - 27 + 17 = 1 - 10 = -9$ **Ответ: -9** **8) $\frac{7}{15} : \left(\frac{6}{10} - \frac{8}{3}\right) + 19 \cdot \frac{2}{31}$** 1) $\frac{6}{10} - \frac{8}{3} = \frac{3}{5} - \frac{8}{3} = \frac{9-40}{15} = -\frac{31}{15}$ 2) $\frac{7}{15} : \left(-\frac{31}{15}\right) = \frac{7}{15} \cdot \left(-\frac{15}{31}\right) = -\frac{7}{31}$ 3) $19 \cdot \frac{2}{31} = \frac{38}{31}$ 4) $-\frac{7}{31} + \frac{38}{31} = \frac{31}{31} = 1$ **Ответ: 1** **12) $\left(\frac{4}{5} + \frac{4}{7}\right)\left(3\frac{3}{8} + 2\frac{11}{4}\right)$** 1) $\frac{4}{5} + \frac{4}{7} = \frac{28+20}{35} = \frac{48}{35}$ 2) $3\frac{3}{8} + 2\frac{11}{4} = 3\frac{3}{8} + 2\frac{22}{8} = 5\frac{25}{8} = 8\frac{1}{8} = \frac{65}{8}$ 3) $\frac{48}{35} \cdot \frac{65}{8} = \frac{6}{7} \cdot \frac{13}{1} = \frac{78}{7} = 11\frac{1}{7}$ **Ответ: 11\frac{1}{7}**