Answer:
x = -8
Explanation:
Set the function f(x)=9-2x equal to 25, and then solve the resulting equation for x:
9 - 2x = 25.
Isolate the -2x term by subracting 9 from both sides:
-2x = 16
Finally, solve for x by dividing both sides by -2:
x = -16/2, or x = -8