What is the greatest common factor of 49 and 42?

Answer 1

One way to approach this is to look at the difference between 42 and 49, which is 7. The greatest common factor of two numbers cannot be larger than the difference between the two numbers and must be a factor of the difference. Since both 42 and 49 are divisible by 7, the greatest common factor is 7.

Another way to determine the greatest common factor is to find all the factors of the numbers and compare them.

The factors of 42 are 1, 2, 3, 6, 7, 14, 21, and 42.

The factors of 49 are 1, 7, and 49.

The common factors are 1 and 7. Therefore, the greatest common factor is 7.

The greatest common factor can also be calculated by identifying the common prime factors and multiplying them together.

The prime factors of 42 are 2, 3, and 7.

The prime factors of 49 are 7 and 7.

The prime factors in common are a single 7, so the greatest common factor is 7

Answer 2

7