
William W. answered 01/19/20
Math and science made easy - learn from a retired engineer
If the roots are x = 9 and x = -3, then the factors are (x - 9) and (x + 3). That means we can multiply these factors together to get a polynomial that has those roots.
f(x) = (x - 9)(x + 3)
f(x) = x2 + 3x - 9x - 27
f(x) = x2 - 6x - 27
Note that there are lots of polynomials that have those roots. I could multiply by another factor, such as 2, or 3, or any number or I could multiply by another binomial like (x - 6) and those polynomials will still have 9 and -3 as roots.