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8.5 Factoring Trinomials of the type x 2 + b x + c. Objective: SWBAT solve a quadratic equation by factoring. Mini Quiz 12. 2. CAHSEE Review. Overview. Factoring x 2 + bx + c…(no GCF) Using the “X” Factor 4 Lines Factoring Reverse FOIL. Factoring with the “X”. Steps:
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8.5 Factoring Trinomials of the type x2 + bx + c Objective: SWBAT solve a quadratic equation by factoring.
Mini Quiz 12 • 2.
Overview Factoring x2 + bx + c…(no GCF) • Using the “X” Factor • 4 Lines Factoring • Reverse FOIL
Factoring with the “X” • Steps: • Draw your “X” • Fill in the a, b, c • (ax2 + bx + c) • 3. Write the Factor Factor x2 – x – 6 a = b = c = 1 1 -1 b -1 + -3 +2 -6 -6 x -6 a·c (x +2)(x – 3)
Factoring with the “X” Factor 1. x2 – 5x + 6 2. x2 – 6x + 9 3. x2 – 16 4. x2 – 6x – 16 (x – 2) (x – 3) (x – 3)2 (x + 4) (x – 4) (x – 8) (x + 2) + x
4 Line Factoring Factor x2 – x – 6 x2 – x – 6 • Steps: • Write the trinomial on top • Write the “b” term on the bottom • Think: “what two things multiply to the “a” term • Think: “What two things multiply to the “c” term • Cross multiply to check x – 3 -3x 2x x + 2 – x (x– 3) (x+ 2)
4 Line Factoring Factor 5. x2 – 10x + 25 6. x2 + 6x – 27 7. x2 + 4x + 4 8. x2 – 4 (x – 5) (x – 5) (x + 9) (x – 3) (x + 2)2 (x + 2) (x – 2)
Factoring by Reverse FOIL ( )( ) x x – 3 + 2 Factor x2 – x – 6 Steps: 1. Set up your ( )( ) 2. Guess factors for F 3. Guess factors for L 4. Check O and I -3x +2x = -x (x– 3)(x+ 2)
Factoring by Reverse FOIL Factor 9. x2 + 11x + 10 10. x2 – 17x + 60 11. x2 – 49 12. x2 – 12x + 36 (x + 10)(x + 1) (x – 12)(x – 5) (x – 7)(x + 7) (x – 6)2
Wrap Up ( ) ( ) Factoring • “X” Factor • Using 4 lines method • Reverse FOIL HW: P. 397 #1-37 EOO; P. 407 #1-6 all; 13-18 all Write DLUQ for notes + x