Name Date Block Score UNIT 8 Study Guide: Factoring & Solving Quadratic Equations Find the greatest common factor. 1. 32 and 64 2. 12 and 21 3. 24x3 and 60x4y2 Factor out the GCF and express your answer as a product. 4. 2x3y2 – 4x2y + 30x2y2 5. 15x2y + 20xy + 25x4y Factor. (Remember to check for a GCF first!): 6. x2 – 81 9. x2 + 10x + 25 13. 9x2 + 30x + 21 17. x4 + x3 – 12x2 7. 10. x2 + 3x – 40 14. 8x2 – 13x – 6 18. 4x2 – 16y2 8. 9x4 – 25 x2 – 8x – 9 12. x2 – 23x + 42 15. 7x2 – 22x + 3 16. 12x2 + 32x – 12 11. x3 + 3x2 - x - 3 19. 3x3 – 4x2 – 12x + 16 Describe and explain how to correct the error. 20. Lester and Michael have both factored the polynomial 12x2 + 16x. Lester factored it as 4x(3x + 4), and Michael factored it as 2x(6x + 8). Who is correct and why? 21. Jimmy says that 16a4 – 81b8 is factored completely as (4a2 + 9b4)(4a2 - 9b4). Cindy says that he is incorrect. Who is correct? Explain. 22. Nick says the factored form of x2 – 3x – 18 = (x + 6)(x – 3). Explain why his solution is incorrect. What would the trinomial need to be for his solution to be correct? Find the quotient. 2 23. If 𝑥 ≠ 5, find the quotient of (40𝑛3 − 16𝑛2 + 25𝑛 − 10) and (5𝑛 − 2). 24. Simplify if 𝑝 ≠ −2: 7𝑝2 +9𝑝−10 25. Find the dimensions of the figure below given the area. 𝑝+2 𝑨 = 𝟖𝒙𝟐 + 𝟏𝟎𝒙 − 𝟑 26. Identify all of the factors of 24𝑛2 − 6𝑛 − 135 when it is factored completely. Circle your answer(s) below. 𝑛 3 (8𝑛 − 20) (8𝑛 + 18) (4𝑛 − 9) (4𝑛 + 9) (2𝑛 − 5) (8𝑛 − 18) 9 27. Identify one of the factors of 36 𝑥 2 − 81 when it is factored completely. Circle your answer below. 9 9 ( 𝑥 + 9) 36 3 ( 𝑥 + 81) 6 1 ( 𝑥 − 9) 2