Question 119446
The given equation is: 

f(x) =>  2 = 3x - 13


This can be written as: f(x) = 3x - 13 - 2 


f(x) = 3x - 15


Let y = f(x) = 3x - 15 


==> y = 3x - 15 


==> 3x = y + 15 


==> {{{x = (y + 15)/3}}}


==> {{{y^-1 = (x + 15)/3}}}