Answer
$f^{-1}(x)=\frac{x+2}{3}$
"MIGUEL HAS ARRIVED"
Work Step by Step
Step 1. For function $f(x)=3x-2$, we can find its inverse as $f^{-1}(x)=\frac{x+2}{3}$
Step 2. For each number in the message, find the numeric value of $f^{-1}(x)$, then use the table to get each letter.
Step 3. The message should be: "MIGUEL HAS ARRIVED"
