Bellwork: Factor Each. 5x2 + 22x + 8 4x2 – 25 81x2 – 36 20x2 – 7x – 6 Algebra II
Factoring Polynomials 4.4 Factoring Polynomials Algebra II
Things to Know Always check for GCF first! Learn your perfect squares: 1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, 196, 225... Learn your perfect cubes: 1, 8, 27, 64, 125, 216, 343, 512... Algebra II
Sum or Difference of Two Cubes (a3 + b3) = (a + b)(a2 – ab + b2) (a3 – b3) = (a – b)(a2 + ab + b2) S O A P same, opposite Always plus Algebra II
Examples: Factor each binomial 1. x3 + 8 (x + 2)(x2– 2x + 4) 2. 8x3 – 1 (2x – 1)(4x2+2x+1) 3. x3 – 27 (x – 3)(x2 + 3x + 9) 4. 8x3 – 125y6 (2x–5y2)(4x2+10xy2+25y4) Algebra II
Examples: Factor each binomial 5. 125 + x3 (5 + x)(25 – 5x + x2) 6. 16x5 – 250x2 2x2(8x3 – 125) 2x2(2x–5)(4x2+10x+25) 7. 81x4 – 16 **Not a perfect cube** (9x2 – 4)(9x2 + 4) (3x–2)(3x+2)(9x2+4) 8. 64a4 – 27a a(64a3 – 27) a(4a–3)(16a2+12a+9) Algebra II
Examples: Factor each binomial 9. 25x4 – 36 **Not a Perfect Cube** (5x2 – 6)(5x2+ 6) 10. 8x3 + 27 (2x +3)(4x2 – 6x+9) 11. 125x9 – 27y3 (5x3–3y)(25x6+15x3y+9y2) 12. 9x8 – 25y6 **Not a Perfect Cube** (3x4 – 5y3)(3x4 + 5y3) Algebra II
Factoring 4 terms by Grouping Group the first two and last two terms Factor the GCF of each group if no GCF, reorder terms and start over Factor out the binomial that is now the GCF Algebra II
Factor by Grouping: 4 Terms Only 1. x3 – 2x2 – 9x + 18 (x3 – 2x2) + (–9x + 18) x2(x – 2) – 9(x – 2) (x – 2)(x2 – 9) (x – 2)(x – 3)(x + 3) 2. bx2 + 2a + 2b + ax2 (bx2 + 2a) + (2b + ax2) No GCF, so reorder. (bx2+2b) + (2a + ax2) b(x2 + 2) + a(2 + x2) (x2 + 2)(b + a) Algebra II
Factor by Grouping: 4 Terms Only 3. 8x3 – 12x2 – 2x + 3 (8x3 – 12x2) + (–2x + 3) 4x2(2x – 3) –1(2x – 3) (2x – 3)(4x2 – 1) (2x – 3)(2x – 1)(2x + 1) 4. 2x3 – x2 + 2x – 1 (2x3 – x2) + (2x – 1) x2(2x – 1) + 1(2x–1) (2x – 1)(x2 + 1) Algebra II
Factor by Grouping: 4 Terms Only 5. x2y2 – 3x2 – 4y2 + 12 (x2y2 – 3x2) + (– 4y2+12) x2(y2 – 3) – 4(y2 – 3) (y2 – 3)(x2 – 4) (y2 – 3)(x – 2)(x + 2) 6. 32x5 – 8x3 + 4x2 – 1 (32x5 – 8x3) + (4x2 – 1) 8x3(4x2 – 1) + 1(4x2 – 1) (4x2 – 1)(8x3 + 1) (2x–1)(2x+1)(2x+1)(4x2–2x+1) Algebra II
Factoring Polynomials: 3 Terms 7. x4 – 8x2 – 9 (x2 – 9)(x2 + 1) (x – 3)(x + 3)(x2 + 1) 8. 3x4 – 8x2 + 4 (3x2 – 2)(x2 - 2) 9. 5x4 – 2x2 – 3 (5x2 + 3)(x2 – 1) (5x2 + 3)(x – 1)(x + 1) 10. 8x4 + 3x2 – 5 (8x2 – 5)(x2 + 1) Algebra II
Factor each. 1. 16x4 – 81 2. 2x6 – 6x4 – 20x2 3. 8x3 – 343 4. x4 – 6x2 – 27 5. 3x3 – 7x2 –12x + 28 6. 3x4 – x2 – 4 Algebra II
Student Journal Pg. 94-95: 20x3 – 220x2 + 600x m5 – 81m 27a3 + 8b3 5t6 + 2t5 – 5t4 – 2t3 y4 – 13y2 - 48 5p3 + 5p – 5p2 – 5 810k4 – 160 a5 + a3 – a2 – 1 2x6 – 8x5 – 42x4 5z3 + 5z2 – 6z – 6 Algebra II
Student Journal Pg. 94-95: 4x3 – 4x2 + x 12x2 – 22x – 20 5m4 – 70m3 + 245m2 12x2 – 22x – 20 3m2 – 48m6 Algebra II
Show that the binomial is a factor of the polynomial Show that the binomial is a factor of the polynomial. Then factor the funtion completely. 15. f(x) = x3 – 13x – 12; x + 1 16. f(x) = 6x3 + 8x2 – 34x – 12; x – 2 17. f(x) = 2x4 – 12x3 + 6x2 + 20x; x – 5 Algebra II