1. Factoring x2 + bx + c
CA 11.0

2. Objective - To factor trinomials in the form x2 + bx + c

3. Factoring Quadratic Trinomials
The FORM is the most important thing!
ax2 + bx + c
The quadratic trinomial is in
STANDARD FORM!
In all the examples we will see today, the value of
a = 1

4. IDENTIFYING a, b, and c a is the COEFFICIENT of x2
b is the COEFFICIENT of x
and c is the constant term
a, b, and c are NUMBERS (not variables).

5. Factoring Quadratic Trinomials
Step 1: Identify a, b, c
Step 2: Create a Factor Cross
a · c b
Step 3: Solve the Factor Cross
**** Since a = 1, these are special cases !
You now have your factors!

6. CHECKING 
You should ALWAYS use “Punnett Rectangles” to check your work!

7. Factoring Quadratic Trinomials
Factor x2 + 19x + 60
a = 1, b = 19, c = 60 60 19
( )( )
Check  +4
+15
(x + 4)(x + 15)

8. Factoring Quadratic Trinomials
Factor x2 + 6x + 8
a = 1, b = 6, c = 8 8 6
( )( )
Check  +2 +4
(x + 2)(x + 4)

9. Factoring Quadratic Trinomials
Factor x2 – 10x + 16
a = 1, b = –10, c = 16 16
–10
(x – 8)(x – 2)
Check  –8 –2

10. Factoring Quadratic Trinomials
Factor x2 + 7x – 18
a = 1, b = 7, c = – 18
– 18 7
(x + 9)(x – 2)
Check  +9 –2