Method 1:
List the factors of each number.
Factors of 28: 2, 4, 7, 14, 28
Factors of 42: 2, 3, 6, 7, 14, 21, 42
Identify the greatest common factor.
The greatest common factor of 28 and 42 is 14.
Method 2:
Write the prime factorization of each number.
28 = 2 × 2 × 7.
42 = 2 × 3 × 7.
The GCF is the product of the common prime factors in each number.
GCF = 2 × 7 = 14.
The greatest common factor of 28 and 42 is 14.
The greatest common factor of 28 and 42 is 14.
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