Let $f: \mathrm{R} \rightarrow \mathrm{R}$ be a function whose inverse is $\frac{x+5}{3}$. What is $f(x)$ equal to?

• A

  $f(x)=3 x+5$
• Correct answer
  B

  $f(x)=3 x-5$
• C

  $f(x)=5 x-3$
• D

  $f(x)$ does not exist

Hence, the correct answer is option: 'B'.