5. Найдите значение выражения: а) 5 5/7 - 1 11/21 + 2 5/14 б) 3 5/6 + 1,5 - 2 1/3

а) $$5 \frac{5}{7} - 1 \frac{11}{21} + 2 \frac{5}{14} = \frac{40}{7} - \frac{32}{21} + \frac{33}{14} = \frac{120}{21} - \frac{32}{21} + \frac{99}{42} = \frac{240}{42} - \frac{64}{42} + \frac{99}{42} = \frac{275}{42} = 6 \frac{13}{42}$$ б) $$3 \frac{5}{6} + 1,5 - 2 \frac{1}{3} = \frac{23}{6} + \frac{3}{2} - \frac{7}{3} = \frac{23}{6} + \frac{9}{6} - \frac{14}{6} = \frac{18}{6} = 3$$