2. Factoring - Difference of Squares

3. What is a Perfect Square

4. What numbers are Perfect Squares? Squares Perfect Squares 1 4 9 16 25 36 49 64 81 100

5. Factoring: Difference of Squares Count the number of terms. Is it a binomial? Is the first term a perfect square? Is the last term a perfect square? Is it, or could it be, a subtraction of two perfect squares? x 2 – 9 = (x + 3)(x – 3) The sum of squares will not factor a 2 +b 2

6. Using FOIL we find the product of two binomials.

7. Rewrite the polynomial as the product of a sum and a difference.

8. Conditions for Difference of Squares Must be a binomial with subtraction. First term must be a perfect square. (x)(x) = x 2 Second term must be a perfect square (6)(6) = 36

9. Recognizing the Difference of Squares Must be a binomial with subtraction. First term must be a perfect square (p)(p) = p 2 Second term must be a perfect square (10)(10) = 100

10. Recognizing the Difference of Squares Must be a binomial with subtraction. First term must be a perfect square (3m)(3m) = 9m 2 Second term must be a perfect square (7)(7) = 49

11. Check for GCF. Sometimes it is necessary to remove the GCF before it can be factored more completely.

12. Removing a GCF of -1. In some cases removing a GCF of negative one will result in the difference of squares.

13. Difference of Squares You Try

15. Factoring - Difference of Squares