The common multiples of 2 and 7 are 14, 28, 42, 56, 70, 84, 98, and so on.
14,28,42,56,70...
42
The first 2 multiples are 42,84.
lcm(2, 7) = 14 → first 3 common multiples are: 14, 28, 42; lcm(2, 8) = 8 → first 3 common multiples are: 8, 16, 24; lcm(7, 8) = 56 → first 3 common multiples are: 56, 112, 168; lcm(2, 7, 8) = 56 → first 3 common multiples are: 56, 112, 168.
2
28 and 56
Any multiple of 14.
28 and 56.
The common multiples of 7, 8, and 8 are the infinite set that includes any multiple of 56. The common multiples are thus 56, 112, 168, 224, 280, and so on.
The LCM is 42.
14, 28, 42