Factor them.
2 x 2 = 4
2 x 7 = 14
2 x 3 x 5 = 30
Combine the factors, eliminating duplicates.
2 x 2 x 3 x 5 x 7 = 420, the LCM
The LCM is: 4,158
The LCM of 4 and 30 is 60.
The LCM is 140.
The LCM is 196.
The LCM is 420.
The LCM is 56.
The LCM is 140.
The LCM is 84.
For 14, 8, 7, 4 the LCM is: 56
The Least Common Multiple (LCM) for 4 12 30 is 60.
The LCM of 2, 4, and 14 is 28
The LCM is 280.