document.write( "Question 367742: I need help with understanding solving systems of linear equations by graphing. I read the chapter and look on sites in the internet and im still not able to understand this part of algebra. A few examples in the text I tried doing myself are:solve by graphign; x-y=3 x+y=5, 2x-y=4 x+y=5, etc. Can someone please help me \n" ); document.write( "

Algebra.Com's Answer #262138 by Edwin McCravy(20055) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"system%28x-y=3%2Cx%2By=5%29\"$
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document.write( "To solve that, make a table of points for each equation:\r\n" );
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document.write( "For  we make a table of arbitrary points:\r\n" );
document.write( "(You make up a value for one of the letters, substitute it,\r\n" );
document.write( "and solve for the other letter.  If you don't know how to\r\n" );
document.write( "do that post again asking how.\r\n" );
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document.write( " x |  y\r\n" );
document.write( "-3 | -6\r\n" );
document.write( " 2 | -1\r\n" );
document.write( " 6 |  3 \r\n" );
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document.write( "We plot them, like this:\r\n" );
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document.write( "Next we get a ruler and draw a straight line through those points:\r\n" );
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document.write( "Next we do the same thing with the other equation:\r\n" );
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document.write( "To solve that make a table of points for it:\r\n" );
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document.write( "For  we make a table of arbitrary points:\r\n" );
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document.write( " x |  y\r\n" );
document.write( "-2 |  7\r\n" );
document.write( " 6 | -1\r\n" );
document.write( "-4 | -7 \r\n" );
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document.write( "We plot them, like this:\r\n" );
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document.write( "Next we get the ruler and draw a straight line through those points,\r\n" );
document.write( "too:\r\n" );
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document.write( "Next we find the coordinates of the point where thos two lines cross by \r\n" );
document.write( "drawing lines from the point where the two lines cross straight to the\r\n" );
document.write( "the x-axis and straight to the y-axis, like this.  I'll draw them in\r\n" );
document.write( "green:\r\n" );
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document.write( "And we see that the green linee ends up at 4 on the x axis and at 1 on\r\n" );
document.write( "the y-axis, and so tjhe answer is x=4, and y=1 \r\n" );
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document.write( "We check by substituting 4 for x and 1 for y in both equations:\r\n" );
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document.write( "x - y = 3         x + y = 5\r\n" );
document.write( "4 - 1 = 3         4 + 1 = 5\r\n" );
document.write( "    3 = 3             5 = 5\r\n" );
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document.write( "Since both equations check, we know we have the correct solution.\r\n" );
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document.write( "Do the others the same way.\r\n" );
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document.write( "Edwin

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