Question 163289
The first step is to replace f(x) with y and then switch the y and the x and solve
y=3x-1 isolate for the x variable

add 1 to both sides

y+1=3x

Divide both sides by 3

1/3y+1/3=x  This is the inverse function

y=x+3/2x
Simplify this equation

2/2x=1x

2/2+3/2=5/2x

Multiply both sides by 2

2y=5x

Divide both sides by 5

2/5y=x