function notation
with function notation most of what is happening is substituting numbers in wherever there is an " x " .
http://www.virtualnerd.com/algebra-1/relations-functions/functions/function-notation/f-of-x-definition
^ This website gives a quick explanation to what function notation is and also it gives an examples of how to do it.
^ This website gives a quick explanation to what function notation is and also it gives an examples of how to do it.