document.write( "Question 118852: Solve the following systems by graphing.\r
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\n" ); document.write( "3x-6y= 9
\n" ); document.write( "x-2y= 3
\n" ); document.write( "Do I graph the these numbers from the equations 6y and 9, 2y and 3? Or do I work out the equations and graph the numbers from the answer to the equations? \r
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Algebra.Com's Answer #86968 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
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Solved by pluggable solver: Solve the System of Equations by Graphing

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\n" ); document.write( " Start with the given system of equations:
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\n" ); document.write( " \"3x-6y=9\"
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\n" ); document.write( " \"1x-2y=3\"
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\n" ); document.write( " In order to graph these equations, we need to solve for y for each equation.
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\n" ); document.write( " So let's solve for y on the first equation
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\n" ); document.write( " \"3x-6y=9\" Start with the given equation
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\n" ); document.write( " \"-6y=9-3x\" Subtract \"3+x\" from both sides
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\n" ); document.write( " \"-6y=-3x%2B9\" Rearrange the equation
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\n" ); document.write( " \"y=%28-3x%2B9%29%2F%28-6%29\" Divide both sides by \"-6\"
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\n" ); document.write( " \"y=%28-3%2F-6%29x%2B%289%29%2F%28-6%29\" Break up the fraction
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\n" ); document.write( " \"y=%281%2F2%29x-3%2F2\" Reduce
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\n" ); document.write( " Now lets graph \"y=%281%2F2%29x-3%2F2\" (note: if you need help with graphing, check out this solver)
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\n" ); document.write( " \"+graph%28+600%2C+600%2C+-10%2C+10%2C+-10%2C+10%2C+%281%2F2%29x-3%2F2%29+\" Graph of \"y=%281%2F2%29x-3%2F2\"
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\n" ); document.write( " So let's solve for y on the second equation
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\n" ); document.write( " \"1x-2y=3\" Start with the given equation
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\n" ); document.write( " \"-2y=3-x\" Subtract \"+x\" from both sides
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\n" ); document.write( " \"-2y=-x%2B3\" Rearrange the equation
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\n" ); document.write( " \"y=%28-x%2B3%29%2F%28-2%29\" Divide both sides by \"-2\"
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\n" ); document.write( " \"y=%28-1%2F-2%29x%2B%283%29%2F%28-2%29\" Break up the fraction
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\n" ); document.write( " \"y=%281%2F2%29x-3%2F2\" Reduce
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\n" ); document.write( " Now lets add the graph of \"y=%281%2F2%29x-3%2F2\" to our first plot to get:
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\n" ); document.write( " Graph of \"y=%281%2F2%29x-3%2F2\"(red) and \"y=%281%2F2%29x-3%2F2\"(green)
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\n" ); document.write( " From the graph, we can see that the two lines are identical (one lies perfectly on top of the other) and intersect at all points of both lines. So there are an infinite number of solutions and the system is dependent.
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