Answer:

1.

Multiples of 7 = 7, 14, 21, 28, 35, 42, 49, 56, 63, 70

Multiples of 14 = 14, 28, 42, 56, 70, 84, 98, 112, 126, 140

LCM = 14

2.

Multiples of 4 = 4, 8, 12, 16, 20, 24, 28, 32, 36, 40

Multiples of 8 = 8, 16, 24, 32, 40, 48, 56, 64, 72, 80

Multiples of 12 = 12, 24, 36, 48, 60, 72, 84, 96, 108, 120

LCM = 14

3.  

Multiples of 14 = 14, 28, 42, 56, 70, 84, 98, 112, 126, 140

Multiples of 7 = 7, 14, 21, 28, 35, 42, 49, 56, 63, 70

Multiples of 4 = 4, 8, 12, 16, 20, 24, 28, 32, 36, 40

Multiples of 2 = 2, 4, 6, 8, 10, 12, 14, 16, 18, 20

LCM = 28