4.221 Выполните сложение: a) -3/7 + 6/7; б) 5/11 + 3/11; в) 3/4 + (-1/6); г) -1 + 4/7; д) -4 + 2 7/8; e) 10 + (-8 5/13); ж) 8 2/7 + (-7 5/14);

a) \(-\frac{3}{7} + \frac{6}{7} = \frac{-3+6}{7} = \frac{3}{7}\) б) \(\frac{5}{11} + \frac{3}{11} = \frac{5+3}{11} = \frac{8}{11}\) в) \(\frac{3}{4} + \left(-\frac{1}{6}\right) = \frac{3}{4} - \frac{1}{6} = \frac{9}{12} - \frac{2}{12} = \frac{7}{12}\) г) \(-1 + \frac{4}{7} = -\frac{7}{7} + \frac{4}{7} = \frac{-7+4}{7} = -\frac{3}{7}\) д) \(-4 + 2\frac{7}{8} = -4 + \frac{23}{8} = -\frac{32}{8} + \frac{23}{8} = \frac{-32+23}{8} = -\frac{9}{8} = -1\frac{1}{8}\) e) \(10 + \left(-8\frac{5}{13}\right) = 10 - 8\frac{5}{13} = 10 - \frac{109}{13} = \frac{130}{13} - \frac{109}{13} = \frac{21}{13} = 1\frac{8}{13}\) ж) \(8\frac{2}{7} + \left(-7\frac{5}{14}\right) = 8\frac{4}{14} - 7\frac{5}{14} = \frac{116}{14} - \frac{103}{14} = \frac{13}{14}\)