Question

How do you know if `y=2x+7` is a function?

Answer 1

Yes, it is a function.

Explanation:

It is a function because there is one unique `y` (also know as `f(x)`) output for each `x` input. That equation is a line:

graph{2x+7 [-10.5, 9.5, -0.84, 9.16]}