Вариант 2. Задание 2: Выполните действия: a) \(\frac{1}{9}\) + \(\frac{2}{9}\), б) \(\frac{3}{7}\) - \(\frac{1}{10}\), в) \(\frac{31}{55}\) - \(\frac{7}{80}\), г) \(\frac{3}{8}\) + \(\frac{1}{14}\) - \(\frac{1}{28}\)

a) \(\frac{1}{9}\) + \(\frac{2}{9}\) = \(\frac{3}{9}\) = \(\frac{1}{3}\)
б) \(\frac{3}{7}\) - \(\frac{1}{10}\) = \(\frac{30}{70}\) - \(\frac{7}{70}\) = \(\frac{23}{70}\)
в) \(\frac{31}{55}\) - \(\frac{7}{80}\) = \(\frac{31 \cdot 16}{55 \cdot 16}\) - \(\frac{7 \cdot 11}{80 \cdot 11}\) = \(\frac{496}{880}\) - \(\frac{77}{880}\) = \(\frac{419}{880}\)
г) \(\frac{3}{8}\) + \(\frac{1}{14}\) - \(\frac{1}{28}\) = \(\frac{3 \cdot 7}{8 \cdot 7}\) + \(\frac{1 \cdot 4}{14 \cdot 4}\) - \(\frac{1 \cdot 2}{28 \cdot 2}\) = \(\frac{21}{56}\) + \(\frac{4}{56}\) - \(\frac{2}{56}\) = \(\frac{23}{56}\)