To find a common multiple of two numbers, we can start by determining their individual multiples and then see which ones they share. For the numbers 5 and 9, their multiples are as follows:
- Multiples of 5: 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, …
- Multiples of 9: 9, 18, 27, 36, 45, 54, 63, …
Now, looking through these two lists, we can see that the first common multiple they both share is 45. This is because 45 appears in both lists:
- 45 is a multiple of 5 (5 x 9 = 45)
- 45 is also a multiple of 9 (9 x 5 = 45)
In fact, 45 is the least common multiple (LCM) of 5 and 9. Other common multiples of 5 and 9 would include higher multiples, such as 90, 135, and so on, which are simply 45 multiplied by positive integers (2, 3, etc.).
Thus, the answer to the question is that a common multiple of 5 and 9 is 45.