63, 126, 189 and so on.
The common multiples of 9 and 21 are 63, 126, 189 and so on.
There are infinitely many multiples of 9 and 21 so it is impossible to list them. One of their multiples is 9*21 = 189.
Any pair of numbers has an infinite set of common multiples. The lowest common multiple of 9 and 21 is 63 and the others are multiples of this, e.g. 63, 126, 189, 252, 315, ...
9
3, 6, 9, 12, 15, 18, and 21 are.
Multiples of 3 are 3, 6, 9 and so on. Multiples of 7 are 7, 14, 21 and so on. The common multiples of 3 and 7 include 21, 42, 63 and so on.
63, 126, 189 and so on.
They are: 63, 126.
The LCM is 63
63.
The LCM is 63.
14 and 21