Final answer:
The common denominator of 14 and 12 is 84.
Step-by-step explanation:
To find the common denominator of 14 and 12, we need to find the smallest number that is divisible by both 14 and 12. We can start by listing the multiples of 14 and 12 until we find a common multiple:
14: 14, 28, 42, 56, 70, 84, 98...
12: 12, 24, 36, 48, 60, 72, 84...
We can see that 84 is the smallest number that appears in both lists. Therefore, the common denominator of 14 and 12 is 84.