Factor the expression 28r + 42s - 35

First, find the GCF of 28, 42, and - 35. When we use the ladder technique, we have: GCF (28, 42, - 35) = 7. We know 7 * 4 is 28, 7 * 6 is 42, 7 * - 5 is - 35. So, we have the following result:

7 (4r + 6r - 5)

We can't factor anymore.