e. Write $f(x)=-x^{3}+9 x^{2}-20 x$ in factored form. \[ f(x)= \] Preview f. Determine the function's horizontal intercepts. Enter your answer as a comma-separated list. \[ x= \] Preview

Step 1 ：First, we find the roots of the function by setting the function equal to zero and solving for x. The roots of the function are the values of x for which f(x) = 0.

Step 2 ：The roots of the function are 0, 4, and 5.

Step 3 ：We can write the function in factored form by setting each factor equal to zero at each root.

Step 4 ：Therefore, the factored form of the function \(f(x)=-x^{3}+9 x^{2}-20 x\) is \(\boxed{f(x) = x*(x - 5)*(x - 4)}\).