we have the following:
[tex]f\mleft(x\mright)=15,000+1.5x[/tex]the inverse is:
[tex]\begin{gathered} y=15000+1.5x \\ x=15000+1.5y \\ 1.5y=x-15000 \\ \frac{3}{2}y=x-15000 \\ y=\frac{2}{3}(x-15000) \end{gathered}[/tex]therefore, the answer is:
[tex]f(x)=\frac{2}{3}(x-15000)[/tex]