factor 8a-28 using GCF

To factor 8a-28 using the greatest common factor (GCF), we need to find the largest number or variable that can be divided evenly into both terms.

First, let's find the GCF of 8 and 28. The factors of 8 are 1, 2, 4, and 8. The factors of 28 are 1, 2, 4, 7, 14, and 28. The GCF of 8 and 28 is 4.

Now let's look at the variable, a. Since there is only one instance of a in both terms, we can consider the GCF of a to be a.

Using the GCF of 4 and a, we can rewrite 8a-28 as:

4(2a-7)