Пошаговое объяснение:
1)5/1*5/6=25/6=4целых1/6
2)8/15 ⋅ 5/14=4/21
3) 5/7 ⋅ 7/12 =5/12
4)2/5 ⋅ 25=10/1
5)9/5 ⋅ 1/9 ⋅ 1/10 =1/50
