Answer: Real.
Explanation:
The third zero, or solutions/roots, is a real zero. It is 6.
To find the answer to this, we will solve by graphing. See attached. The graph intercepts the x-axis, when y = 0 ("zeros") three times. These points have x-values of 4, -4, and our last one of 6.
We can substitute this back into the equation and see that it is true.
f(x) = x³ - 6x² - 16x + 96
f(6) = (6)³ - 6(6)² - 16(6) + 96
0 = 216 - 216 - 96 + 96
0 = 0