1. Factoring
Trinomials

2. Factor x2 + 9x + 20

3. x2 + 9x + 20
( )( ) 5 4 x x
Find 2 numbers with a product of 20, and can be combined by addition to equal 9
1 x 20
2 x 10
4 x 5

4. Check with FOIL
( x + 5)(x + 4) x2
+ 4x
+ 5x
+ 20
x2 + 9x + 20

5. x2 + 8x + 16
( )( ) 4 4 x x
Find 2 numbers with a product of 16, and can be combined by addition to equal 8
1 x 16
2 x 8
4 x 4

6. Check with FOIL
( x + 4)(x + 4) x2
+ 4x
+ 4x
+ 16
x2 + 8x + 16

7. The – means that one sign will be negative and one will be positive
x2 + 2x - 3 -
( )( ) 1 + 3 x x
The – means that one sign will be negative and one will be positive
Find 2 numbers with a product of 3, and can be combined by addition to equal 2
1 x 3

8. Check with FOIL
( x - 1)(x + 3) x2
+ 3x
+ -x
+ -3
x2 + 2x - 3

9. The – means that one sign will be negative and one will be positive
x2 + x - 12 -
( )( ) 3 + 4 x x
The – means that one sign will be negative and one will be positive
Find 2 numbers with a product of 12, and can be combined by addition to equal 1
1 x 12
2 x 6
3 x 4

10. Check with FOIL
( x - 3)(x + 4) x2
+ 4x
+ -3x
+ -12
x2 + x - 12

11. The – means that one sign will be negative and one will be positive
x2 - 2x - 8 -
( )( ) 4 + 2 x x
The – means that one sign will be negative and one will be positive
Find 2 numbers with a product of 8, and can be combined by addition to equal 2
1 x 8
2 x 4

12. Check with FOIL
( x - 4)(x + 2) x2
+ 2x
+ -4x
+ -8
x2 - 2x - 8

13. x2 - 6x + 9 -
( )( ) 3 - 3 x x
The + in front of the 9 and the – in front of the 6 means that both signs will be negative
Find 2 numbers with a product of 9, and can be combined by addition to equal 6
1 x 9
3 x 3

14. Check with FOIL
( x - 3)(x - 3) x2
+ -3x
+ -3x
+ 9
x2 - 6x + 9

15. x2 - 7x + 10 -
( )( ) 2 - 5 x x
The + in front of the 10 and the – in front of the 7 means that both signs will be negative
Find 2 numbers with a product of 10, and can be combined by addition to equal 7
1 x 10
2 x 5

16. Check with FOIL
( x - 2)(x - 5) x2
+ -5x
+ -2x
+ 10
x2 - 7x + 10