Answer:
f(x) = (x - 9)(x + 2) = x^2 - 7x - 18
Explanation:
If the x-intercepts are -2 and 9, then the factors of this quadratic are (x + 2) and (x - 9). Multiplying these two factors together, we get:
f(x) = (x - 9)(x + 2) = x^2 - 9x + 2x -18, or
f(x) = (x - 9)(x + 2) = x^2 - 7x - 18