Skills CheckFactor.1. x2 + 2x – 15

2. x2 + 14x + 24

3. 2x2 + 6x – 36

4. 3x2 + 13x + 4

5. 4x2 + 16x + 15

Difference of Difference of Two Perfect Two Perfect

SquaresSquares

Difference of SquaresDifference of Squares

A binomial with a subtraction sign in between terms that are both PERFECT SQUARES

2 2a b

To Factor Difference of To Factor Difference of SquaresSquares

• One parenthesis is a plus and one is a minus.

• Take the square root of each term.

a b a b

9 13 9 13 n n

21. 81 169nExample

2 22. 4 121x y 2 11 2 11 x y x y

Example

22 25 x

23. 2 50xExample

2 5 5 x x

24. 3 48b 23 16 b

Example

3 4 4 b b

45. 1296b 2 236 36 b b

Example

2 36 6 6 b b b

Perfect Square Trinomials

•These are special too, but can be done using our usual method of factoring trinomials

26. 6 9 x x

23 x

Example

27. 9 12 4 y y

23 2 y

Example