1) To find the inverse function of this f(x) function, we need to presume this is a bijective function, and then follow these steps all the way through it:
2)
[tex]\begin{gathered} f(x)=5x+18 \\ \\ y=5x+18\:\:\:\:Swap\:the\:variables \\ \\ x=5y+8\:\:Isolate\:the\:y-term\:on\:the\:left\:side \\ \\ 5y+18-18=x-18\:\:\:Subtract\:18\:from\:both\;sides \\ \\ 5y=x-18\:\:\:Divide\:both\:sides\:by\:5 \\ \\ \frac{5y}{5}=\frac{x}{5}-\frac{18}{5}\:\:\:Simplify: \\ \\ y=\frac{x-18}{5}\:\:\:Write\:the\:proper\:notation \\ \\ f^{-1}(x)=\frac{x-18}{5} \end{gathered}[/tex]Thus, this is the answer.
