д) 9 5/7 : 1 23/28

д) \(9 \frac{5}{7} : 1 \frac{23}{28} = \frac{68}{7} : \frac{51}{28} = \frac{68}{7} \cdot \frac{28}{51} = \frac{68 \cdot 28}{7 \cdot 51} = \frac{1904}{357} = \frac{16 \cdot 119}{3 \cdot 119} = \frac{16}{3} = 5 \frac{1}{3}\)