Answer
$x^3-12x-16$
Work Step by Step
Let us consider that $a$ is a zero of a function with multiplicity $b$. Then this factor of the function can be expressed as: $(x-a)^b$.
We are given that the degree is $3$, and the zeros are −2 (multiplicity 2) and 4 (multiplicity 1).
Therefore, we can write the equation of the function as:
$f(x)=(x+2)^2(x-4)\\=(x^2+4x+4)(x-4)\\=x^3-12x-16$
