Разберем каждое действие по порядку:
a) \(\frac{11}{17} + \frac{3}{17} = \frac{11+3}{17} = \frac{14}{17}\)
б) \(\frac{39}{100} + \frac{12}{100} = \frac{39+12}{100} = \frac{51}{100}\)
в) \(\frac{7}{15} - \frac{3}{15} = \frac{7-3}{15} = \frac{4}{15}\)
г) \(\frac{9}{17} - \frac{1}{17} = \frac{9-1}{17} = \frac{8}{17}\)
д) \(\frac{5}{7} - \frac{2}{7} = \frac{5-2}{7} = \frac{3}{7}\)
е) \(\frac{8}{10} - \frac{7}{10} = \frac{8-7}{10} = \frac{1}{10}\)