Answer:
y(x) = x + 4
Step-by-step explanation:
A function rule is nothing more than a process that correlates changes in input to changes in output. If y is the output and x is the input, the function must be of the form y(x). Since "The output is four more than the input", the value of y is always 4 units greater than the value of x. The function rule is:
[tex]y(x) = x + 4[/tex]