Вариант III. Выполните сложение (1-2): 1. a) 5/13 + (-7/13); б) 3/11 + (-8/11); в) 9/17 + 13/17

a) \(\frac{5}{13} + \left(-\frac{7}{13}\right) = \frac{5-7}{13} = \frac{-2}{13} = -\frac{2}{13}\) б) \(\frac{3}{11} + \left(-\frac{8}{11}\right) = \frac{3-8}{11} = \frac{-5}{11} = -\frac{5}{11}\) в) \(\frac{9}{17} + \frac{13}{17} = \frac{9+13}{17} = \frac{22}{17}\)