№2. Выполните вычитание дробей: 1) \frac{2}{21} - \frac{1}{14} = 2) \frac{7}{9} - \frac{1}{6} = 3) \frac{5}{17} - \frac{1}{34} = 4) \frac{4}{5} - \frac{11}{15} = 5) \frac{3}{18} - \frac{4}{27} = 6) \frac{3}{8} - \frac{1}{12} = 7) \frac{11}{14} - \frac{1}{7} = 8) \frac{11}{63} - \frac{1}{9} = 9) \frac{12}{15} - \frac{2}{5} = 10) \frac{11}{27} - \frac{1}{9} =

№2. Выполните вычитание дробей:

1. \frac{2}{21} - \frac{1}{14} = \frac{2 \cdot 2}{21 \cdot 2} - \frac{1 \cdot 3}{14 \cdot 3} = \frac{4}{42} - \frac{3}{42} = \frac{4-3}{42} = \frac{1}{42}
2. \frac{7}{9} - \frac{1}{6} = \frac{7 \cdot 2}{9 \cdot 2} - \frac{1 \cdot 3}{6 \cdot 3} = \frac{14}{18} - \frac{3}{18} = \frac{14-3}{18} = \frac{11}{18}
3. \frac{5}{17} - \frac{1}{34} = \frac{5 \cdot 2}{17 \cdot 2} - \frac{1}{34} = \frac{10}{34} - \frac{1}{34} = \frac{10-1}{34} = \frac{9}{34}
4. \frac{4}{5} - \frac{11}{15} = \frac{4 \cdot 3}{5 \cdot 3} - \frac{11}{15} = \frac{12}{15} - \frac{11}{15} = \frac{12-11}{15} = \frac{1}{15}
5. \frac{3}{18} - \frac{4}{27} = \frac{3 \cdot 3}{18 \cdot 3} - \frac{4 \cdot 2}{27 \cdot 2} = \frac{9}{54} - \frac{8}{54} = \frac{9-8}{54} = \frac{1}{54}
6. \frac{3}{8} - \frac{1}{12} = \frac{3 \cdot 3}{8 \cdot 3} - \frac{1 \cdot 2}{12 \cdot 2} = \frac{9}{24} - \frac{2}{24} = \frac{9-2}{24} = \frac{7}{24}
7. \frac{11}{14} - \frac{1}{7} = \frac{11}{14} - \frac{1 \cdot 2}{7 \cdot 2} = \frac{11}{14} - \frac{2}{14} = \frac{11-2}{14} = \frac{9}{14}
8. \frac{11}{63} - \frac{1}{9} = \frac{11}{63} - \frac{1 \cdot 7}{9 \cdot 7} = \frac{11}{63} - \frac{7}{63} = \frac{11-7}{63} = \frac{4}{63}
9. \frac{12}{15} - \frac{2}{5} = \frac{12}{15} - \frac{2 \cdot 3}{5 \cdot 3} = \frac{12}{15} - \frac{6}{15} = \frac{12-6}{15} = \frac{6}{15} = \frac{2}{5}
10. \frac{11}{27} - \frac{1}{9} = \frac{11}{27} - \frac{1 \cdot 3}{9 \cdot 3} = \frac{11}{27} - \frac{3}{27} = \frac{11-3}{27} = \frac{8}{27}

Ответ: 1) \frac{1}{42}; 2) \frac{11}{18}; 3) \frac{9}{34}; 4) \frac{1}{15}; 5) \frac{1}{54}; 6) \frac{7}{24}; 7) \frac{9}{14}; 8) \frac{4}{63}; 9) \frac{2}{5}; 10) \frac{8}{27}