For functions, we learn that they have a certain rule. We start with an input, something mysterious happens, and then, we get an output. This mysterious part represents the changes we make to go from the input to the output. For example, if I had an input of 1, I could get an output of 3. Something’s happened here. You might have thought that I just added 2 to the number. Well, here’s some other inputs. If I put in a 2, I get out a 5. And if I put in a 3, I get out a 7. So the question is, what’s happening to our inputs? So, based on these inputs and outputs, what rule or expression could we write for this function? If I put in x, I would get out y. What are we doing to x? That’s the rule I want you to write here.

f(x) = y

dont understand