Unit 8, Lesson 7a

(x+3)(x+2) Multiplying Binomials (FOIL) FOIL = x 2 + 2x + 3x + 6 = x 2 + 5x + 6

Factoring Trinomials in 3 Steps Step 1: List all pairs of numbers that multiply to equal 12. Factor x 2 + 7x + 12 into two binomial factors. 12 = 1 12 = 2 6 = 3 4

Step 2: Choose the pair that adds up to = 1 12 = 2 6 = 3 4 Factor x 2 + 7x + 12 into two binomial factors. Factoring Trinomials in 3 Steps

Step 3: Use those numbers to build your binomials. 12 = 1 12 = 2 6 = 3 4 ( x + )( x + ) 34 Factor x 2 + 7x + 12 into two binomial factors. Factoring Trinomials in 3 Steps

Step 1: Find the factors of 15. Step 2: Identify the pair that has a sum of 8. Factors of 15 Sum of Factors 1 and and 5 8 (x + 3)(x + 5)

Since the middle term is negative, find the negative factors of 20. (c – 5)(c – 4) Factors of 20 Sum of Factors –1 and –20 –21 –2 and –10 –12 –4 and –5 –9

Factor each trinomial. Watch out for signs! 1)x x )x 2 –10x + 24 Factor These Trinomials