Question

What is the input when f(x)=18?

Answer 1

Answer: The input is 5.

Step-by-step explanation: Since both are functions of f(x), you can set 9x-27 equal to 18 and then solve the equation. 9x-27=18, add 27 to both sides to get 9x=45, divide both sides by 9, x=5.

:)

Answer 2

Answer is 5


You replace the f(x) with 18 which makes it into (18)=9x-27 then you do basic algebra from there.