Find all real zeros (if any) and state the multiplicity of each.
$f(x) = 4x^5 - 16x^4 + 16x^3$
$x = \text{none}$
Enter a real zero, then a comma, and then its multiplicity. If the function has more than one real zero, enter a
comma before the next zero. For example, if the function has the following zeros:
2 with multiplicity 1
-3 with multiplicity 4
6 with multiplicity 2
then "(2,1), (-3,4), (6,2)" should be entered.
The list can begin with any of the zeros. Enter "none" if the function has no real zeros.