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Graphing Linear Equations: Examples (page 3 of 4)

Sections: Making a T-chart, Plotting the points and drawing the line, Examples


  • Graph y = (5/3)x 2
  • First I'll do the T-chart.

    Since I am multiplying x by a fraction, I will pick x-values that are multiples of 3, so the denominator will cancel out and I won't have fractions.

      

    T-chart

      

      

      

      

    Then I'll plot my points and draw my graph:

      

     y = -(5/3)x - 2

  • Graph y = 7 5x
      
      Copyright Elizabeth Stapel 2000-2011 All Rights Reserved
  •   

    First I'll do the T-chart.

      

    T-chart

      

    This equation is an example of a situation in which you will probably want to be particular about the x-values you pick. Because the x is multiplied by a relatively large value, the y-values grow quickly. For instance, you probably wouldn't want to use x = 5 or x = 3. You could pick larger x-values if you wished, but your graph would get awfully tall.
      

      

      

      

    And as you can see, the graph is pretty tall already:

     

    y = 7 - 5x

  • Graph y = 3
  • Don't let this one scare you. Yes, there is no "x" in the equation, but that's okay. Just think about it this way: it doesn't matter what x-value you pick; y will always be 3.

      

    Your T-chart would look something like this:

      

    T-chart

      

    Then your graph would look like this:

      y = 3

Any time you have a "y equals a number" equation, with no x in it, the graph will always be a horizontal line.

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Cite this article as:

Stapel, Elizabeth. "Graphing Linear Equations: Examples." Purplemath. Available from
    http://www.purplemath.com/modules/graphlin3.htm. Accessed
 

 



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