[tex]2y - 4 = 10\\
2y=10+4=14\\
y=\cfrac{14}{2}=7
[/tex]
So. For every value of x, y is a constant. Can you find any point, x, where it has more than ONE value for y? NO. Every point on the x-axis corresponds to EXACTLY one value of Y. That is the definition of a function.
