Find the inverse of f(x) = (3x - 6)/2

First, imagine that f(x) is written as y: 

y = (3x -6)/2

swap the variables over so you write y as x and x as y:

x = (3y - 6)/2

Next, solve for x (try and get the y on its own on the right hand side)

2x = 3y - 6

2x + 6 = 3y

(2x + 6)/3 = y

Finally, swap the x and y back over to receive your answer!

f(x)' = (2x + 6)/3

where f(x)' is the inverse of f(x)