document.write( "Question 207312: Graph the 2 lines below; and from the graph, read off the point of intersection.
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Algebra.Com's Answer #156751 by Edwin McCravy(20055) $\"\"$ $\"About$

You can put this solution on YOUR website!
Graph the 2 lines below; and from the graph, read off the point of intersection.
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document.write( "Get 3 points on the first line:\r\n" );
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document.write( "Arbitrarily select, say, x = 0 and substitute 0 for x in the\r\n" );
document.write( "first equation:\r\n" );
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document.write( "So the first point on the first line is (x,y) = (0,3)\r\n" );
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document.write( "Arbitrarily select, say, x = -2 and substitute -2 for x in the\r\n" );
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document.write( "So the second point on the first line is (x,y) = (-1,-1)\r\n" );
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document.write( "Arbitrarily select, say, x = 3 and substitute 3 for x in the\r\n" );
document.write( "first equation:\r\n" );
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document.write( "So the third point of the first line is (x,y) = (3,9)\r\n" );
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document.write( "Plot those three points:\r\n" );
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document.write( "Get a ruler and draw a straight line through them:\r\n" );
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document.write( "Get 3 points on the second line:\r\n" );
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document.write( "Arbitrarily select, say, x = 1 and substitute 1 for x in the\r\n" );
document.write( "second equation:\r\n" );
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document.write( "So the first point on the second line is (x,y) = (1,6)\r\n" );
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document.write( "Arbitrarily select, say, x = -1 and substitute -1 for x in the\r\n" );
document.write( "second equation:\r\n" );
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document.write( "So the second point on the second line is (x,y) = (-1,4)\r\n" );
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document.write( "Arbitrarily select, say, x = 4 and substitute 4 for x in the\r\n" );
document.write( "second equation:\r\n" );
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document.write( "So the third point of the second line is (x,y) = (4,9)\r\n" );
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document.write( "Plot those three points:\r\n" );
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document.write( "Take your ruler and draw a straight line through\r\n" );
document.write( "those three points:\r\n" );
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document.write( "Now take your ruler and draw 2 lines from the point\r\n" );
document.write( "where the two lines cross, one directly to the x-axis\r\n" );
document.write( "and one directly to the y-axis:\r\n" );
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document.write( "Notice that these last two lines hit the x-axis\r\n" );
document.write( "at 2 and the y-axis at 7.  So the solution is\r\n" );
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document.write( ", , sometimes written\r\n" );
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document.write( "(x,y) = (2,7)\r\n" );
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document.write( "To check we substitute  and \r\n" );
document.write( "in both equations:\r\n" );
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document.write( "It checks the first equation.  Now let's see if\r\n" );
document.write( "it checks the second equation.\r\n" );
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document.write( "So it checks both equations, so it is correct.\r\n" );
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document.write( "Edwin

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