Algebra 1 Graphing Absolute Values with Number Lines
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An Absolute Line
Graphing Absolute Values with Number Lines

 

 We know how to graph things like:

 

 
 But what do we do with:
 

 
 What we need is a formula to use 
 to get rid of the absolute value lines.
 Here it is ...
 

 
 The first formula is pretty easy to remember,
 but it would be nice if there was a trick
 to help us keep the other two straight.
 
 -10 < X + 3 < 10 which has X in the middle,
 takes up LESS space to write than the other one
 so it goes with less than: (|x + 3|>10)
 
 X + 3 > 10 or X + 3 < -10 which has two pieces,
 takes up a GREATER amount of space than the other one
 so it goes with greater than (|X + 3|>10)
 
 And from there, you can find X.
 
 Oh sure you can, 
 we did this kind of stuff two pages ago.
 
 Example:
 
 Solve for X and graph ...

 
 So:

 

 
 So the graph looks like this ...
 

 
 Example:
 
 Solve for X and graph ...
 

 

 So:
 

 
 DID YOU SEE THE LESS THAN AND GREATER THAN SIGNS
 CHANGE DIRECTION WHEN WE DIVIDED BY -5?
 
 So:

 

 The graph of this is:
 

 

   copyright 2005 Bruce Kirkpatrick

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