Answer:
The LCM (least common multiple) of 8 and 14 is 56.
The LCM of 6 and 21 is 42.
The LCM of 20 and 15 is 60.
The LCM of 28 and 16 is 112.
The LCM of 12 and 42 is 84.
Explanation:
1. 8, 16, 24, 32, 40, 48, 56
14, 28, 42, 56
2. 6, 12, 18, 24, 30, 36, 42
21, 42
3. 20, 40, 60
15, 30, 45, 60
4. 28, 56, 84, 112
16, 32, 48, 64, 80, 96, 112
5. 12, 24, 48, 60, 72, 84
42, 84
In order to easily find the LCM of a number, just keep adding that number to itself, same for the other number, as well. Just keep adding until you find a number that they have in common. For example, the LCM of 6 and 9 is 18.
6 + 6 = 12 + 6 = 18 (6 • 3 = 18)
9 + 9 = 18 (9 • 2 = 18)
It doesn't have to be added the same number of times, just the lowest number that they have in common.
Hope this helps! :)