Mathematics I - Old Questions

iii) Let the function \( f: \mathbb{R} \to \mathbb{R} \) be defined by \( f(x) = 3x + 5 \) then its inverse is

a) x    b) \( \frac{1}{3} \)    c) \( \frac{-5}{3} \)    d) \( \frac{x-5}{3} \)