584 a) 3/5 - 4/5; 2/7 - (-3/7); -1/9 - (-5/9); б) 6/7 - 8/7; 3/9 - (-2/9); -5/8 - (-3/8); в) -1/12 - (-5/12); 2/15 - 7/15; 4/9 - 5/9

Решим примеры на вычитание дробей:

а) \(\frac{3}{5} - \frac{4}{5} = \frac{3-4}{5} = \frac{-1}{5} = -\frac{1}{5}\) \(\frac{2}{7} - \left(-\frac{3}{7}\right) = \frac{2}{7} + \frac{3}{7} = \frac{2+3}{7} = \frac{5}{7}\) \(-\frac{1}{9} - \left(-\frac{5}{9}\right) = -\frac{1}{9} + \frac{5}{9} = \frac{-1+5}{9} = \frac{4}{9}\) б) \(\frac{6}{7} - \frac{8}{7} = \frac{6-8}{7} = \frac{-2}{7} = -\frac{2}{7}\) \(\frac{3}{9} - \left(-\frac{2}{9}\right) = \frac{3}{9} + \frac{2}{9} = \frac{3+2}{9} = \frac{5}{9}\) \(-\frac{5}{8} - \left(-\frac{3}{8}\right) = -\frac{5}{8} + \frac{3}{8} = \frac{-5+3}{8} = \frac{-2}{8} = -\frac{2}{8} = -\frac{1}{4}\) в) \(-\frac{1}{12} - \left(-\frac{5}{12}\right) = -\frac{1}{12} + \frac{5}{12} = \frac{-1+5}{12} = \frac{4}{12} = \frac{1}{3}\) \(\frac{2}{15} - \frac{7}{15} = \frac{2-7}{15} = \frac{-5}{15} = -\frac{5}{15} = -\frac{1}{3}\) \(\frac{4}{9} - \frac{5}{9} = \frac{4-5}{9} = \frac{-1}{9} = -\frac{1}{9}\)

Ответ: a) -1/5, 5/7, 4/9; б) -2/7, 5/9, -1/4; в) 1/3, -1/3, -1/9

Ты молодец! У тебя всё получится!