Answer
a. $f(x)=500+80x$.
b. $\frac{x-500}{80} = f^{-1}(x)$
c. $f^{-1}(1220)=9$
Work Step by Step
A function that models an investigator's fee as a function of hours the investigator spends working on a case is a retainer fee plus an hourly rate of an investigator
thus,
a.
$f(x)=500+80x$.
b.
$f(x) = 500 + 80x$
$y= 500+ 80x$
$y-500 = 80x$
$\frac{y-500}{80} = x$
$\frac{x-500}{80} = f^{-1}(x)$
$f^{-1}$ represents a function of an hour an investigator spends working on a case as a function of the investigator's fee
c.
$\frac{1220-500}{80} = f^{-1}(1220)$,
$f^{-1}(1220)=9$
the investigator works on a case for $9$hr for a fee of $1220$ received
