To find a common denominator of 14 and 35, we need to determine the least common multiple (LCM) of these two numbers.
- The prime factorization of 14 is \(2 \times 7\).
- The prime factorization of 35 is \(5 \times 7\).
To find the LCM, we take the highest power of each prime factor:
- The highest power of 2 is \(2^1\).
- The highest power of 5 is \(5^1\).
- The highest power of 7 is \(7^1\).
Now, multiply these together: \[ LCM = 2^1 \times 5^1 \times 7^1 = 2 \times 5 \times 7 = 70. \]
None of the options provided (9, 15, 16, 20) are common denominators of 14 and 35. The correct common denominator is 70, which is not listed among your options.