Question

Given f(x) = the quantity of 4x plus 1, divided by 3 solve for f-1(3).

Answer 1

f-1(3) is the inverse

Answer 2

\(\bf f(x)={\color{red}{ y}}=\cfrac{4{\color{blue}{ x}}+1}{3}\qquad inverse\implies
{\color{blue}{ x}}=\cfrac{4{\color{red}{ y}}+1}{3}\)

solve for "y" to get the inverse, then plug in "-3" into it