2. 1. Write as a Binomial: (9-w)(9+w) 2. Write each square as a trinomial: (6c-1) ² 3. Simplify: (y+4)(y+10)

3. a ²-b²  (a+b)(a-b) (First #)² - (Second #) ² = (sum of 2 squares) x (their difference)

4. Ex: 9a ² -4b ² =( 3a + 2b )(3a-2b) 3a is the square root of 9a ² and 2b is the square root of 4b ²

5. Ex: 36-25

6. 81-16 *** After you factor the number the first time, if there still is an a ²-b² in the subtraction binomial, you have to factor again until there are no squares left. ***

7. a ²+(-)2ab+b²  (a+(-)b)² If the middle number in the equation equals twice the square root of a times the square root of b, then you can factor it.

8. Ex: a ² +2a+1 = ( a+1 ) ² a and 1 are the square roots of the first and last numbers

9. Ex: u ² -6u+9

10. Ex: b ² +12b+4 This trinomial can’t be factored this way because the middle number does not equal twice the product of the first and last number.

11. Ex: 121c^4-264c ² +144 ^4 means to the fourth power****

12. x²+(-)bx+c  (x + factor of b that adds to c) (x +(-) factor of b that adds to c)

13. Ex: x ² +8x+15 = (x+ 3 ) (x+ 5 ) 5 and 3 add up to 8, and are a factor pair of 15.

14. Ex: x ² -10x+24

15. Ex: y ² +20yz+91z ²

16. Ex: x^4-15x ² y ² -16y^4