document.write( "Question 271957: I have to write the slope-intercept form equation of the line described:\r
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Algebra.Com's Answer #199001 by Edwin McCravy(20055)\"\" \"About 
You can put this solution on YOUR website!
I have to write the slope-intercept form equation of the line described:\r
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document.write( "This is a vertical line, which is the only case where \r\n" );
document.write( "there is no slope-intercept form.  However there is an\r\n" );
document.write( "equation for it.\r\n" );
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document.write( "Let's begin by drawing the line whose equation is y = 5.\r\n" );
document.write( "I'll draw it green.  I'll also plot the point (-4,1)\r\n" );
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document.write( "Now we'll draw a blue line through (-4,1) which is perpendicular \r\n" );
document.write( "to the green line  \r\n" );
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document.write( "The way to determine its equation is to look at several points\r\n" );
document.write( "on that blue vertical line and to observe what one thing is true about\r\n" );
document.write( "all of them:\r\n" );
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document.write( "Lets look at some points on that blue vertical line:\r\n" );
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document.write( "Notice what all those points\r\n" );
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document.write( "(-4,5), (-4,3), (-4,1), (-4,-3), (-4,-5), (-4,-8)\r\n" );
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document.write( "have in common.  They all have their x-coordinates\r\n" );
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document.write( "equal to -4.  So all we do is write that the x\r\n" );
document.write( "value on every point on that line is -4, and to do that\r\n" );
document.write( "we simply write the simple equation\r\n" );
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document.write( "x = -4 \r\n" );
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document.write( "That equation is only true for points on that line,\r\n" );
document.write( "so that is the equation of the blue vertical line.  There\r\n" );
document.write( "is no slope-intecept for it because there is no \"m\",\r\n" );
document.write( "because vertical lines do not have a slope.  There is\r\n" );
document.write( "also no \"b\" because vertical lines have no y-intercept.\r\n" );
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document.write( "So the only thing we can do is write the simple equation\r\n" );
document.write( "which describes every point on that blue vertical line, which\r\n" );
document.write( "is x = -4.\r\n" );
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document.write( "Edwin
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