There is an expression some people use that says, “what you put into it is what you get out of it.” people might use this expression to describe your skills at a sport or activity and how that relates to the amount of time and effort you spend practicing that activity. does this expression apply to functions? how? give an example to support your answer.

The expression, "What you put into it is what you get out of it," is most used to describe your skills and effort, but it also applies to functions too. When I think of input and output I imagine a function table which shows your input and then an output that is related.
    
    For example, if you were to do y = 6x ( x = 4) you'll get 24.
          y = 4x
 |  Input - Output |
           6 - ?             
         12 - 48
           9 - 36

 Hope this helps!