Ответ: смотри решение
Заполним равенства:
10 ⋅ 5 = 50
5 ⋅ 10 = 50
50 : 5 = 10
50 : 10 = 5
10 ⋅ 7 = 70
7 ⋅ 10 = 70
70 : 7 = 10
70 : 10 = 7
10 ⋅ 9 = 90
9 ⋅ 10 = 90
90 : 9 = 10
90 : 10 = 9