Answer
The values of x for which f(x) = 9 include
x = 2.46035
x = -2.23018 + 2.44956i
x = -2.23018 - 2.44956i
In comma-seperated list
x = [3.83543, (-2.23018 + 2.44956i), (-2.23018 - 2.44956i)]
Explanation
We are told that
f(x) = x³ + 2x² - 18
We are then asked to find the values of x for which f(x) = 9
When f(x) = 9,
9 = x³ + 2x² - 18
x³ + 2x² - 18 = 9
x³ + 2x² - 18 - 9 = 0
x³ + 2x² - 27 = 0
Now, we have to solve this polynomial
On inputing this on a clculator, the 3 answers for this polynomial expression include
x = 2.46035
x = -2.23018 + 2.44956i
x = -2.23018 - 2.44956i
Hope this Helps!!!
