1 Найдите разность: a) \(\frac{4}{5} - \frac{3}{4}\); б) \(\frac{3}{10} - \frac{2}{7}\); в) \(\frac{2}{3} - \frac{1}{7}\); г) \(\frac{5}{9} - \(\frac{1}{3}\).

Найдем разность дробей.

1. \(\frac{4}{5} - \frac{3}{4} = \frac{4 \cdot 4}{5 \cdot 4} - \frac{3 \cdot 5}{4 \cdot 5} = \frac{16}{20} - \frac{15}{20} = \frac{16 - 15}{20} = \frac{1}{20}\)
2. \(\frac{3}{10} - \frac{2}{7} = \frac{3 \cdot 7}{10 \cdot 7} - \frac{2 \cdot 10}{7 \cdot 10} = \frac{21}{70} - \frac{20}{70} = \frac{21 - 20}{70} = \frac{1}{70}\)
3. \(\frac{2}{3} - \frac{1}{7} = \frac{2 \cdot 7}{3 \cdot 7} - \frac{1 \cdot 3}{7 \cdot 3} = \frac{14}{21} - \frac{3}{21} = \frac{14 - 3}{21} = \frac{11}{21}\)
4. \(\frac{5}{9} - \frac{1}{3} = \frac{5}{9} - \frac{1 \cdot 3}{3 \cdot 3} = \frac{5}{9} - \frac{3}{9} = \frac{5 - 3}{9} = \frac{2}{9}\)

Ответ:

1. \(\frac{1}{20}\);
2. \(\frac{1}{70}\);
3. \(\frac{11}{21}\);
4. \(\frac{2}{9}\).