Answer:
y = (9/8)(x +4)(x -2)
Explanation:
When the x-intercepts are "a" and "b", you know factors of the function are (x-a) and (x-b). So, we can write the function as ...
... y = k(x -(-4))(x -2) = k(x +4)(x -2) . . . . . for some scale factor k
We can find k using the given point.
... -9 = k(0 +4)(0 -2) = -8k
Dividing by -8 gives ...
... 9/8 = k
The desired function is ...
... y = (9/8)(x +4)(x -2)
... = (9/8)(x² +2x -8)