Answer:
18
Step-by-step explanation:
You can start by looking at their prime factors:
9 = 3²
6 = 2·3
The LCM is the product of the highest powers of the unique factors, so is ...
LCM = 2·3² = 18
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Alternate solution
The LCM can also be found as the product of the numbers, divided by their greatest common factor. From the above list of factors, we know that 3 is a factor common to both numbers (also the greatest common factor). So the LCM is ...
LCM(9, 6) = 9×6/GCF(9,6) = 54/3 = 18
