Question

2/ *=14/21 и 5/*=15/21

Answer 1

14 : 2 = 7 - доп.множ.
21 : 7 = 3 - знаменатель
2/3 = 14/21 - доп.множ. 7

15 : 5 = 3 - доп.множ.
21 : 3 = 7 - знаменатель
5/7 = 15/21 - доп.множ. 3