Typo alerts

There are two typos that I have found that make a difference. The first one is in Example 2 of the Extra Practice Factoring and Dividing worksheet. That one I put the correction on the board (the third line of the example should have -6 not +6). The new correction is on the Finite Differences/Technique Review worksheet. Problem 5 has a table of numbers. The point (3, 15) should be (3, -15). Left unchanged you will have a great deal of difficulty practicing the finite differences technique.