In the next sections, I'll be telling you more about these equations and you'll be learning about graphing and much, much more!  Tell them what they'll be learning, Bob!

Welllll... In the next exciting and action packed lessons, our lucky students will be learning about

Equations of lines
Slopes
Graphing
and
Finding equations

Information like this would usually sell for $500...  But, for our students today we have a special deal.  All of these lessons and more for the just 14 easy payments of $59.99!

(I really need to stop watching infomercials while I'm writing these lessons.)

So, how can we be sure that a specific point is really ON a line?

Graphing could be one way to get a general idea... But, there are two problems with this

1) I haven't shown you how to graph lines yet.
2) You can't always be sure with just the graph.

Check it out:

Is the point ( -1, 2 ) on the line 2x - 3y = 6 ?

Here's the graph:
(Don't worry, I'll show you how to graph these soon.  I know you're very excited about all this!)

a graph of the line 2x - 3y = 6 showing that the point ( -1, 2 ) is not on the line

But, what if it's not so easy to be sure?