Question 269390
A graph is just a way to show every possible
way that 2 unknown quantities can be related
Every point on a graph is an (x,y) point
the x was how you got to that point going
horizontally. The y is how you got there 
going vertically.
To build understanding:
{{{y = 7}}} is an equation, it just doesn't involve x
It should say to you "I don't care what x is -all
I care about is that {{{y = 7}}}
Now I'll plot it:
{{{ graph( 500, 500, -2, 5, -2, 10, 7) }}}
Looking at the graph, every point on the horizontal line
says "I'm at (x,7), and I don't care what x is, because
x can be anything you want. If you want x to be 3.7025,
then I will be the point (3.7025,7), and that will be
on the line {{{y = 7}}}
Now suppose I draw the line {{{y = 0}}}. That's the 
horizontal line that says "I don't care what x is as
long as y is always zero. 
Any point on this line looks like (x,0), and it's
actually the x-axis
If I choose (4.7319,0), that is on the x-axis
Does this help any? Always go back to what 
you're sure of and build your understanding
up to where it should be -there's no other way