Lines are used and seen everyday!  There are lines everywhere.  When people think of a line, they usually think of a solid bar.  The truth is that lines are made up of an infinite number of points that stretch infinitely in opposite directions.  If you ask someone to draw a line, the will probably draw something like this:                         .  This is wrong.  A line, remember, stretches infinitely in opposite directions.
            
Vertical and Horizontal Lines.
            
	Before getting to the complicated world of graphing lines with equations, first we will graph simple lines.	A Coordinate Plane is used to graph lines on.  It consists of a horizontal axis called the x-axis, and a vertical axis called the y-axis.  The two lines meet at a point called the origin.  The graph of X = 5 ( See fig. 1) would be a vertical line even though the x - axis is a horizontal line.  The same for the graph of y = 5 ( See fig. 2), except that line would be horizontal while the y - axis is vertical.  .
            
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Graphing.
            
	To graph a point on the coordinate plane, you need an ordered pair.  An ordered pair is expressed as follows: (3, 4).  The numbers inside tell you where to place the point.  The first number represents the x-axis.  It shows  in which direction to move and how many units to move ( See fig. 3).  The second number represents the y-axis. It too shows in which direction to move and how many units to move it ( See fig. 4).  .
            
	To graph, you first need an equation such as Y = 2x + 5 ( this type of equation will be covered in more detail).  To compute a set of points to plot on the graph, a table of values must be used.  In this table the x - value is a constant set of numbers.  Plug in those numbers in place of the "x" in the equation Y = 2x + 5.  Solve the equation for "y".  Now that you have your table completed, plotting points can be used to construct a line.  With the x/y values, ordered pairs such as (-3, -1) and (-2, 1) can be used in the graph.