9.3 Factoring Trinomomials

Rainbow Method (2 nd degree Polynomial) 2

Example 3-1a Factor Factors of 12 Sum of Factors 1, 12 2, 6 3, The correct factors are 3 and 4. Write the pattern. Answer: and

Example 3-1a Check You can check the result by multiplying the two factors. FOIL method FOIL Simplify.

Example 3-1b Factor Answer:

Example 3-2a Factor Factors of 27 Sum of Factors –1, –27 –3, –9 –28 –12 The correct factors are –3 and –9. Write the pattern. Answer: and

Example 3-2b Factor Answer:

Example 3-3a Factor Factors of –18 Sum of Factors 1, –18 –1, 18 2, –9 –2, 9 3, –6 –3, 6 –17 17 – 7 7 – 3 3 The correct factors are –3 and 6.

Example 3-3a Write the pattern. Answer: and

Example 3-3b Factor Answer:

Example 3-4a Factors of –20 Sum of Factors 1, –20 –1, 20 2, –10 –2, 10 4, –5 –4, 5 –19 19 – 8 8 – 1 1 The correct factors are 4 and –5. Factor

Example 3-4a Write the pattern. Answer: and

Example 3-4b Factor Answer:

Practice Problems Page 493 Problems Problems 17-32, (factor only)