Проверочная работа № 2 2 Найдите сумму: б) 2/3 + 5/11 + 7/11.

б) \[\frac{2}{3} + \frac{5}{11} + \frac{7}{11} = \frac{2}{3} + (\frac{5}{11} + \frac{7}{11}) = \frac{2}{3} + \frac{12}{11} = \frac{2 \cdot 11}{3 \cdot 11} + \frac{12 \cdot 3}{11 \cdot 3} = \frac{22}{33} + \frac{36}{33} = \frac{22 + 36}{33} = \frac{58}{33} = 1\frac{25}{33}\]