3) 2 6/72 + 3 9/76 =

Сократим дроби: \(\frac{6}{72}=\frac{1}{12}\), \(\frac{9}{76}\) не сокращается.

\(2\frac{1}{12}+3\frac{9}{76}=5+\frac{1}{12}+\frac{9}{76}\).

НОК(12, 76) = stresses: \(228\).

\(\frac{1}{12}=\frac{19}{228}\), \(\frac{9}{76}=\frac{27}{228}\).

\(5+\frac{19}{228}+\frac{27}{228}=5+\frac{46}{228}=5+\frac{23}{114}=5\frac{23}{114}\).

Ответ: \(5\frac{23}{114}\)