Answer: x =6 1/3
Explanation:
Whichever value of x from the given option that make f(x) = 0 is the zero of f(x). x = 6 1/3 satisfies this, you can check by replacing 6 1/3 by x in the equation. 6 1/3 can be written as 19/3
f(19/3) = 9(19/3)² - 54(19/3) - 19
= 9(361/9) - 54(19/3) - 19
= 361 - 342 - 19
= 0.
The remaining values don't give 0.