#### Answer

6
Remember the GCF of any two numbers is the greatest number that can be multiplied by a whole number to equal both of the numbers applied. In this case, we need to find the GCF of 12 and 18. The number 6 is a multiple of 18 by 3, and a multiple of 12 by 2. The clause is not true for any number greater than 6, making 6 the greatest common factor.

#### Work Step by Step

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