Проверочная работа № 3 1 Найдите разность: a) \(\frac{4}{5} - \frac{3}{5}\); б) \(\frac{3}{10} - \frac{2}{7}\); в) \(\frac{2}{3} - \frac{1}{7}\); г) \(\frac{5}{9} - \frac{1}{3}\); д) \(\frac{5}{6} - \frac{5}{12}\); e) \(\frac{2}{13} - 0\).

Решим примеры:

a) \(\frac{4}{5} - \frac{3}{5}\) = \(\frac{4 - 3}{5}\) = \(\frac{1}{5}\)

б) \(\frac{3}{10} - \frac{2}{7}\) = \(\frac{3 \cdot 7}{10 \cdot 7} - \frac{2 \cdot 10}{7 \cdot 10}\) = \(\frac{21}{70} - \frac{20}{70}\) = \(\frac{21 - 20}{70}\) = \(\frac{1}{70}\)

в) \(\frac{2}{3} - \frac{1}{7}\) = \(\frac{2 \cdot 7}{3 \cdot 7} - \frac{1 \cdot 3}{7 \cdot 3}\) = \(\frac{14}{21} - \frac{3}{21}\) = \(\frac{14 - 3}{21}\) = \(\frac{11}{21}\)

г) \(\frac{5}{9} - \frac{1}{3}\) = \(\frac{5}{9} - \frac{1 \cdot 3}{3 \cdot 3}\) = \(\frac{5}{9} - \frac{3}{9}\) = \(\frac{5 - 3}{9}\) = \(\frac{2}{9}\)

д) \(\frac{5}{6} - \frac{5}{12}\) = \(\frac{5 \cdot 2}{6 \cdot 2} - \frac{5}{12}\) = \(\frac{10}{12} - \frac{5}{12}\) = \(\frac{10 - 5}{12}\) = \(\frac{5}{12}\)

е) \(\frac{2}{13} - 0\) = \(\frac{2}{13}\)

Ответ: a) \(\frac{1}{5}\); б) \(\frac{1}{70}\); в) \(\frac{11}{21}\); г) \(\frac{2}{9}\); д) \(\frac{5}{12}\); е) \(\frac{2}{13}\).