Mathematically, when you calculate the inverse function (f-1(x)), you’re switching the “inputs” (x) and the “outputs” (f(x)) and then re-solving the equation. So, you’d start with something like:
x = 3*f-1(x) + 3
x - 3 = 3*f-1(x)
(x - 3)/3 = f-1(x)
Your inverse formula would be (x - 3)/3. Hope this helps! (Hopefully Brainly doesn’t mess up the text format.)