What is the equation of the invers of?

Presentation is wide open to doubt.
Is it meant to be :-
1.
g(x) = (3/4) x + 2 ?????
OR
2.
g(x) = 3/(4x) + 2 ????
OR
3.
g (x) = 3 / [ 4x + 2 ] ?????

For argument sake let us go with

1.
y = f (x) = (3/4) x + 2
Let g (y) = x______i.e. g is inverse of y
(3/4) x + 2 = y
3x + 8 = 4y
3x = 4y - 8
x = [ 4y - 8 ] / 3
g (y) = [ 4y - 8 ] / 3
g (x) = [ 4x - 8 ] / 3______inverse function

PS
Remember to use brackets!!!!!!

y = ¾x + 2

rearrange to solve for x
x = (4/3)y - 8/3

g⁻¹(x) = (4/3)x - 8/3