The output is 2 less than the input

Question

how the heck do i write a function rule for that

Answer 1

In a function, the input is "x" and the output is "y".

So, let's replace the words "output" and "input" in your sentence with "x" and "y".

It now reads:

Y is 2 less than X.

Almost there... translate is = equals, 2 less than X as x-2.

y=x-2

Put in function notation:

f(x)=x-2