Answer:
(x^2-9)
Step-by-step explanation:
To have roots plusminus 3, the factors need to be (x+3) and (x-3)
You can FOIL those and multiply those out to get x^2-9.
Or you can remember the rule of Difference of Squares and know that the first term minus squared the second term squared is equal to first term + second term and first term minus second term.
Basically, (a^2-b^2) = (a+b)(a-b)
This does not work if it is (a^2+b^2)
