1. Do Now Find the GCF of each set of numbers. 1)34, 51 2)36, 72 3)21, 42, 56

2. Finding the GCF For variables that ALL terms have in common, the GCF is always the smallest exponent that you have of each variable. 1)x 3, x 5 2)z 4, z 2

3. 3)12a 5, 18a 2 4)18xy, 36y 2 5)36x 2 y, 54 xy 2 z 6)12a 5 c 7, 24a 3 b 2 c, 18a 10 b 4 c 3

5. Factoring Using the GCF Factoring with a GCF is basically the opposite of using the distributive property. 4a (3a + 4) 12a 2 + 16a

6. Factoring Using the GCF Now we’re going to start with:12a 2 + 16a and end up with:4a (3a + 4) Steps: 1)Find the GCF of ALL of the terms. The GCF will be on the outside of the ( ). 2)Divide each original term by the GCF to get each term inside the ( ). * You always have to have the same number of terms inside the ( ) as you started with.

7. 1)FACTOR 25a 2 + 15a. Find the GCF and divide each term 25a 2 + 15a = 5a ( ___ + ___ ) Check your answer by distributing.

8. 2)Factor 18x 2 – 12x 3. Divide each term by the GCF 18x 2 - 12x 3 = 6x 2 ( ___ – ___ ) Check your answer by distributing.

9. 3) Factor 28a 2 b + 56abc 2. 28a 2 b + 56abc 2 = 28ab ( __ + ___ ) Check your answer by distributing.

10. 4) Factor 28a 2 + 21b – 35b 2 c 2 28a 2 + 21b - 35b 2 c 2 = 7 ( ___ + ___ – ____ ) Check your answer by distributing.

11. Factor 3x 2 y – 27x 5 y 3 z + 18x 3 y 7 z 2

12. Factor 16xy 2 - 24y 2 z + 40y 2 1.2y 2 (8x – 12z + 20) 2.4y 2 (4x – 6z + 10) 3.8y 2 (2x - 3z + 5) 4.8xy 2 z(2 – 3 + 5)

13. Factor 20x 2 - 24xy 1.x(20 – 24y) 2.2x(10x – 12y) 3.4(5x 2 – 6xy) 4.4x(5x – 6y)

14. Homework Chapter 9 Packet Pgs. 529 #’s 1 – 12