1. Выполните вычитание. 7 4 1) a) 15-15 17 5 6)21-21 15 7 B) 22-22 28 18 г) 75-75 1. Найдите:

Ответ:

1) a) \[\frac{7}{15} - \frac{4}{15} = \frac{7-4}{15} = \frac{3}{15} = \frac{1}{5}\]

б) \[\frac{17}{21} - \frac{5}{21} = \frac{17-5}{21} = \frac{12}{21} = \frac{4}{7}\]

в) \[\frac{15}{22} - \frac{7}{22} = \frac{15-7}{22} = \frac{8}{22} = \frac{4}{11}\]

г) \[\frac{28}{75} - \frac{18}{75} = \frac{28-18}{75} = \frac{10}{75} = \frac{2}{15}\]

2) a) \[\frac{4}{5} - \frac{1}{3} = \frac{4 \cdot 3}{5 \cdot 3} - \frac{1 \cdot 5}{3 \cdot 5} = \frac{12}{15} - \frac{5}{15} = \frac{12-5}{15} = \frac{7}{15}\]

б) \[\frac{3}{4} - \frac{1}{3} = \frac{3 \cdot 3}{4 \cdot 3} - \frac{1 \cdot 4}{3 \cdot 4} = \frac{9}{12} - \frac{4}{12} = \frac{9-4}{12} = \frac{5}{12}\]

в) \[\frac{4}{5} - \frac{3}{4} = \frac{4 \cdot 4}{5 \cdot 4} - \frac{3 \cdot 5}{4 \cdot 5} = \frac{16}{20} - \frac{15}{20} = \frac{16-15}{20} = \frac{1}{20}\]

г) \[\frac{3}{4} - \frac{4}{9} = \frac{3 \cdot 9}{4 \cdot 9} - \frac{4 \cdot 4}{9 \cdot 4} = \frac{27}{36} - \frac{16}{36} = \frac{27-16}{36} = \frac{11}{36}\]

3) a) \[\frac{9}{14} - \frac{2}{7} = \frac{9}{14} - \frac{2 \cdot 2}{7 \cdot 2} = \frac{9}{14} - \frac{4}{14} = \frac{9-4}{14} = \frac{5}{14}\]

б) \[\frac{5}{12} - \frac{1}{3} = \frac{5}{12} - \frac{1 \cdot 4}{3 \cdot 4} = \frac{5}{12} - \frac{4}{12} = \frac{5-4}{12} = \frac{1}{12}\]

в) \[\frac{7}{10} - \frac{2}{5} = \frac{7}{10} - \frac{2 \cdot 2}{5 \cdot 2} = \frac{7}{10} - \frac{4}{10} = \frac{7-4}{10} = \frac{3}{10}\]

г) \[\frac{17}{100} - \frac{1}{10} = \frac{17}{100} - \frac{1 \cdot 10}{10 \cdot 10} = \frac{17}{100} - \frac{10}{100} = \frac{17-10}{100} = \frac{7}{100}\]

Ответ: