Ответ:

105/3. 75/3

35/5. 25/5

7/7. 5/5

1. 1

НСК(105;75)=3•5•7•3•5²=7.875

28/2. 18/2

14/2. 9/3

7/7. 3/3

1. 1

НСК(28;18)=2²•7•2•3•3=504