Given Numbers: 15, 18
Identify the Prime Factors of 15 and 18 by Prime Factorization
Identify the Prime Factors of 15 and 18 by Prime Factorization
- Prime Factorization of 15: 15 = 3 x 5 = 31 x 51
- Prime Factorization of 18: 18 = 2 x 3 x 3 = 21 x 32
Determine the Prime Factor(s) that are common to the Prime Factorization of each number:
- 3 is the only Prime Factor common to the Prime Factorizations of 15 and 18
Determine the least number of occurrences of 3 among the Prime Factorizations:
- 3 occurs at least 1 time in each Prime Factorization
As a result, the Greatest Common Factor (GCF) of 15 and 18 is equal to 3, which equals 3 raised to the power of its least number of occurrences or smallest exponent among the Prime Factorizations:
- GCF (15, 18) = 31
- GCF(15, 18) = 3
Therefore, the Greatest Common Factor of 15 and 18 by Prime Factorization = 3