Factoring Quadratics

Using the “X ” method

Warm - up1. (x - 7)2 = x 2 - 14x + 49

3. (2k + 3)2 = 4k 2 + 12k + 9

5. ( t - 6 )( t + 6 )

= t2 - 36

2. (m + 8)2 = m 2 + 16m + 64

4. (3z - 5)2 = 9z 2 - 30k + 25

6. ( 5y 2 - 2 )( 5y2+ 2) = 25y2 - 4

Quadratics with a leading coefficient of 1

Factors of 12 Sum of factors

1 and 12 132 and 6 83 and 4 7

1. Factor x2 + 7x + 12

(x + 3) ( x + 4)

1. Factor x2 + 7x + 12

(x + 3) ( x + 4)12

437

1. Factor x2 + 21x + 20

(x + 20) ( x + 1)20

12021

Your Turn!

1. Factor x2 - 6x + 8

(x - 4) ( x - 2)8

-2-4-6

1. Factor x2 - x - 12

(x + 3) ( x - 4)-12

-43-1

Your Turn!

1. Factor x2 - 9x + 20

(x - 5) ( x - 4)20

-4-5-9

1. Factor x2 - 7x + 10

(x - 2) ( x - 5)10

-5-2-7

Your Turn!

1. Factor x2 + 2x - 15

(x - 3) ( x + 5)-15

5-32

1. Factor x2 + 6x - 7

(x - 1) ( x + 7)-7

7-16

Your Turn!

Classwork