Factoring Trinomials

1
Section 6.7

• Factoring Trinomials

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Multiplying (x 8)(x 3)Result x2 11x
24 Factoring x2 11x 24Result (x
8)(x 3)
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Factoring Trinomials Remember

• FOIL- (First Outer Inner Last)
• Used to multiply binomials
• ex. (x 8)(x 3)
• Result x2 11x 24
• Factor Trinomial x2 11x 24
• Will be in the form (x a)(x b) where a and b
  are constants

4
Factor

• ex. x2 11x 24
• (x 8)(x 3)
• How?
• (Undo the FOIL method)
• x2- product of the first terms
• 11x- sum of the outer terms and inner terms
• 24- product of last terms
• (Remember to use the sign that is in front of
  number)
• This will be the case when factoring all
  trinomials.

5
Steps for Factoring

• Factor out GCF if it exists
• Factor out (-1) if the variable with the highest
  power is negative
• Factor trinomial into a product of binomials.
  (Undo FOIL method.)

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Factoring Trinomials

• CASE 1- 1st term has coefficient of 1

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Factoring Trinomials

• CASE 2- Factor out GCF lst

8
Factoring Trinomials

• CASE 3- Coefficient of Trinomial is not 1.

9
Factoring Trinomials

• CASE 4- 1st term has coefficient of -1

10
Factoring Trinomials

• CASE 5- Factoring by Substitution