1. Factoring Trinomials

2. Please note! Example: x2 – 5x – 6 (x + 1)(x – 6) Example: x2 – 5x + 6

3. Multiple Variables - Example 1:
Factor: a2 + 5ab + 4b2 4
1 · 4
Look for factors of 4 that
ADD
2 · 2 to
positive 5
(a + 1b)
(a + b)
(a + 4b)
(a + b)
or (a + b)(a + 4b)

4. Now you try! Example: x2 – 13xy + 36y2 (x – 4y)(x – 9y)

5. More Factoring Trinomials

6. Example 1: Factor: 6x2 + 17x + 5 6x2 + 17x + 5 Look for factors of 30
that
6x2 + 17x + 5
= 6x2 + 2x + 15x + 5
ADD to
positive 17
= (6x2 + 2x) + (15x + 5)
= 2x(3x + 1) + 5(3x + 1)
= (2x + 5)(3x + 1)

7. Example 2: Factor: 4h2 + 8h – 5 4h2 + 8h – 5 = 4h2 – 2h + 10h – 5
Look for factors of -20
that
4h2 + 8h – 5
ADD
= 4h2 – 2h + 10h – 5 to
positive 8
= (4h2 – 2h) + (10h – 5)
= 2h(2h – 1) + 5(2h – 1)
= (2h + 5)(2h – 1)

8. Example 3: Factor: 6r2 – 13r + 6 6r2 – 13r + 6 = 6r2 – 9r – 4r + 6
Look for factors of 36
that
6r2 – 13r + 6
ADD to
negative 13
= 6r2 – 9r – 4r + 6
= (3r – 2)(2r – 3)

9. Now you try! 1) 2x2 – 3x – 5 = (2x – 5)(x + 1) 2) 4b2 + 4b – 15