Answer:
zero of the function is 4
Explanation:

To find the zeros , we replace f(x) with 0

Factor the right side of the equation and solve for x
product is 16 and sum is 8
-4 times -4 is 16
-4 plus -4 is -8, the factors are -4 and -4
set each factor =0 and solve for x
x-4 =0, x=4