1. Modeling Monday Follow Up Class Averages: PeriodOld TreesNew Trees 1 (Alg. 1)1421894 2 (Alg. 1)1133512 3 (Geo)1136582 5 (Geo) 1141568

2. Warmups Solve the system: 1. 2. 3. Multiply: Subtract:

3. 8-2 GCF & FACTORING BINOMIAL Objective: To find the GCF and factor using the GCF.

4. Factors Factor: a number or variable that divides evenly into your original number. Example 1: Find the factors of 72. 1 72 2 36 3 24 4 18 6 12 8 9

5. Some terms to know Prime: Only factors are 1 & itself Composite: Having more than 2 factors Write the prime numbers up to 20: 1, 2, 3, 5, 7, 11, 13, 17, 19

6. FACTOR TREE (for composite #s) 384 2 192 2 96 2 48 224 2 12 2 6 2 3 22222223 Prime factorization

7. TOO 1) 202) 36 225 2233 Hints If it is an even, it is divisible by 2 If you add the digits and the answer is divisible by 3, then the original number is divisible by 3 If it ends in 0 or 5, it is divisible by 5 Stop trying when the answer is smaller than the number you divided by

8. Example 2: Factoring with Variables 81b 2 c 3 9 9 3 3 3333bbccc TOO 32abc 3 22222abccc

9. Greatest Common Factor (GCF) Make a factor tree and multiply together what they have in common 8028 2 40 2 14 2 20 2 7 2 10 2 5 22 = 4 =GCF

10. GCF: Biggest number that will divide evenly into all of the numbers With variables, take the smallest exponent 32xy 2 z, 48x 3 y 4 22222, 22223 GCF: 16xy 2 TOO for Homework 18xp 2, 48x 4

11. Challenge Problem – find the GCF

12. FACTOR: WORK BACKWARDS! 1) 3x + 3 2) 2x 2 – 6x 3) 2ab – 9a 1) 3(x + 1) 2) 2x(x – 3) 3) a(2b – 9) Question Answer: GCF (÷ out)

13. EXAMPLE 3 9x 2 y + 6xy 2 GCF: 3xy Divide it to the outside of some parenthesis Then write what you have left inside of the parenthesis for each term 3xy( + ) 3xy(3x+2y) 3x2y

14. Quick TOO

15. Homework Pg. 495 # 15 – 26, 37 - 40