Check. When the leading coefficient is negative, we factor the negative out as part of the GCF. When the leading coefficient is negative, the GCF will be negative.

How do you know when to factor out a negative?

The laws of multiplication state that when a negative number is multiplied by a positive number, the product will be negative. So, if considering a factor pair of a negative product, one of these factors must be negative and the other factor must be positive.

What is the rule for GCF?

To find the GCF of a set of numbers, list all the factors of each number. The greatest factor appearing on every list is the GCF. For example, to find the GCF of 6 and 15, first list all the factors of each number. Because 3 is the greatest factor that appears on both lists, 3 is the GCF of 6 and 15.