We need to determine the equation solving for x, because x is the inverse of y. The inverse of the function is written as y⁻¹
y = 9x - 4
switch the side, so x will be on the left side
9x - 4 = y
move 4 to the right side, substraction becomes addition
9x = y + 4
move 9 to the right side, multiplication becomes division
x = [tex] \cfrac{y+4}{9} [/tex]
Switch x with invers of y, switch y with x. The invers is as written below.
y⁻¹ = [tex] \cfrac{x+4}{9} [/tex]
