9) 4 7/8 : (2 3/4 + 1 10/19)

9) \(4\frac{7}{8} : (2\frac{3}{4} + 1\frac{10}{19}) = \frac{39}{8} : (\frac{11}{4} + \frac{29}{19}) = \frac{39}{8} : (\frac{209}{76} + \frac{116}{76}) = \frac{39}{8} : \frac{325}{76} = \frac{39}{8} \cdot \frac{76}{325} = \frac{39 \cdot 19}{2 \cdot 325} = \frac{3 \cdot 19}{2 \cdot 25} = \frac{57}{50} = 1\frac{7}{50}\)
Ответ: 57/50