Suppose you need to write a sum of numbers as a product of their GCF and another sum. What is the GCF of the numbers in the other sum? Explain

Example:

5 + 10

GCF is 5

(5 * 1) + (5 * 2) = 5 (1 + 2)

The GCF in the other sum? ... there is none because it has already been factored

example:

15 + 45

GCF = 15

(15 * 1) + (15 * 3) = 15 (1 + 3)