Вычислите: 24 - 3/64 - 3/4

21. $$24 - \frac{3}{64} - \frac{3}{4} = 24 - (\frac{3}{64} + \frac{3 \cdot 16}{4 \cdot 16}) = 24 - (\frac{3}{64} + \frac{48}{64}) = 24 - \frac{51}{64} = \frac{24 \cdot 64 - 51}{64} = \frac{1536 - 51}{64} = \frac{1485}{64} = 23\frac{13}{64}$$ **Ответ:** $23\frac{13}{64}$ 22. $$\frac{18}{35} : 12 + \frac{1}{10} = \frac{18}{35} \cdot \frac{1}{12} + \frac{1}{10} = \frac{3 \cdot 6}{35 \cdot 2 \cdot 6} + \frac{1}{10} = \frac{3}{35 \cdot 2} + \frac{1}{10} = \frac{3}{70} + \frac{1}{10} = \frac{3}{70} + \frac{1 \cdot 7}{10 \cdot 7} = \frac{3+7}{70} = \frac{10}{70} = \frac{1}{7}$$ **Ответ:** $\frac{1}{7}$ 23. $$\frac{27}{40} : 18 + \frac{9}{16} = \frac{27}{40} \cdot \frac{1}{18} + \frac{9}{16} = \frac{3 \cdot 9}{40 \cdot 2 \cdot 9} + \frac{9}{16} = \frac{3}{80} + \frac{9}{16} = \frac{3}{80} + \frac{9 \cdot 5}{16 \cdot 5} = \frac{3+45}{80} = \frac{48}{80} = \frac{3 \cdot 16}{5 \cdot 16} = \frac{3}{5}$$ **Ответ:** $\frac{3}{5}$ 24. $$\frac{9}{14} \cdot (\frac{17}{24} - \frac{5}{12}) = \frac{9}{14} \cdot (\frac{17}{24} - \frac{5 \cdot 2}{12 \cdot 2}) = \frac{9}{14} \cdot (\frac{17}{24} - \frac{10}{24}) = \frac{9}{14} \cdot \frac{7}{24} = \frac{9 \cdot 7}{14 \cdot 24} = \frac{9 \cdot 7}{2 \cdot 7 \cdot 24} = \frac{9}{2 \cdot 24} = \frac{9}{48} = \frac{3 \cdot 3}{3 \cdot 16} = \frac{3}{16}$$ **Ответ:** $\frac{3}{16}$ 25. $$\frac{7}{39} \cdot (\frac{1}{7} + \frac{6}{49}) = \frac{7}{39} \cdot (\frac{1 \cdot 7}{7 \cdot 7} + \frac{6}{49}) = \frac{7}{39} \cdot (\frac{7}{49} + \frac{6}{49}) = \frac{7}{39} \cdot \frac{13}{49} = \frac{7 \cdot 13}{39 \cdot 49} = \frac{7 \cdot 13}{3 \cdot 13 \cdot 7 \cdot 7} = \frac{1}{3 \cdot 7} = \frac{1}{21}$$ **Ответ:** $\frac{1}{21}$ 26. $$\frac{3}{11} + \frac{15}{17} : \frac{11}{34} = \frac{3}{11} + \frac{15}{17} \cdot \frac{34}{11} = \frac{3}{11} + \frac{15 \cdot 2 \cdot 17}{17 \cdot 11} = \frac{3}{11} + \frac{30}{11} = \frac{3+30}{11} = \frac{33}{11} = 3$$ **Ответ:** $3$ 27. $$ (\frac{4}{5} - \frac{8}{15}) \cdot \frac{5}{12} = (\frac{4 \cdot 3}{5 \cdot 3} - \frac{8}{15}) \cdot \frac{5}{12} = (\frac{12}{15} - \frac{8}{15}) \cdot \frac{5}{12} = \frac{4}{15} \cdot \frac{5}{12} = \frac{4 \cdot 5}{15 \cdot 12} = \frac{4 \cdot 5}{3 \cdot 5 \cdot 3 \cdot 4} = \frac{1}{3 \cdot 3} = \frac{1}{9}$$ **Ответ:** $\frac{1}{9}$