II. Which of the following is a quadratic equation? For those that are, identify the value of a, b, and c. 1. x2 - 7x-9=0 6. (x-2)(x+5) = x(x+8) 2. X-5=0 7. (x+3)(x-3) = 7 3. 4x2 - 7x==20 8. 3x(x2 + 3x - 5) = 0 4. (x+3)2 = 2(x - 5) 9. (x - 2)2 + 6 = 4x + 1 5. x2 + 2x + 1 = -7x + 8 10. (x + 2)3= x(x2 - 10x + 25) paki sagot po:)​