А)8-8, 16, 24, 32, 40

12-12, 24, 36, 48, 60

НОК-24

Б)2-2,4,6,8...70

5-5,10,15,20...70

7-7,14,21,28...70

НОК-70

В)2-2,4,6,8,10...28

4-4,8,12,16,20,24,28

7-7,14,21,28,35,42

НОК-28

Ответ:

а) НОК (8;12) = 24

Кратное 8: 8, 16, 24, 32, 40, 48, 56, 64, 72...

Кратное 12: 12, 24, 36,48, 60, 72...

б) НОК (2; 5; 7) = 70

Кратное 2: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 62, 64, 66, 68, 70, 72...

Кратное 5: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 80...

Кратное 7: 7, 14, 21, 28, 35, 42, 49, 56, 63, 70, 77...

в) НОК (2; 4; 7) = 28

Кратное 2: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32...

Кратное 4: 4, 8, 12, 16, 20, 24, 28, 32, 36...

Кратное 7: 7, 14, 21, 28, 35, 42...