document.write( "Question 81637: I'm learning how to write my \"results\" in slope-intercept form. And I'm having a little difficulty trying to get these worked out and was wondering if I could get some assistance.\r
\n" ); document.write( "\n" ); document.write( "(0,5),m= -3/5\r
\n" ); document.write( "\n" ); document.write( "(-1,3) and (4,-2)
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\n" ); document.write( "\n" ); document.write( "I could really use the step by step process of how to do this, if possible. Thank you. \n" ); document.write( "
Algebra.Com's Answer #58515 by Edwin McCravy(20054)\"\" \"About 
You can put this solution on YOUR website!
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document.write( "I'm learning how to write my \"results\" in \r\n" );
document.write( "slope-intercept form. And I'm having a little\r\n" );
document.write( "difficulty trying to get these worked out and \r\n" );
document.write( "was wondering if I could get some assistance. \r\n" );
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document.write( "(0,5), m = \"-3%2F5\" \r\n" );
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document.write( "Substitute in the point slope formula:\r\n" );
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document.write( "   y - y1 = m(x - x1)\r\n" );
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document.write( "where x1 = 0 and y1 = 5\r\n" );
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document.write( "   y - 5 = \"-3%2F5\"(x - (0) )\r\n" );
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document.write( "   y - 5 = \"-3%2F5\"x\r\n" );
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document.write( "       y = \"-3%2F5\"x + 5\r\n" );
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document.write( "That's the equation in the slope-intercept\r\n" );
document.write( "form because we can compare it with\r\n" );
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document.write( "       y = mx + b\r\n" );
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document.write( "and see that its slope m is \"-3%2F5\" and its\r\n" );
document.write( "y-intercept (0,b) is the point (0,5)\r\n" );
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document.write( "1. (-1, 3) and (4,-2)\r\n" );
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document.write( "We first plot those two points and draw a line \r\n" );
document.write( "through them to find out if it is vertical or\r\n" );
document.write( "not. The equations of all lines can be placed\r\n" );
document.write( "in slope-intercept form except the equations\r\n" );
document.write( "for vertical lines. This is the graph we get:\r\n" );
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document.write( "\"graph%28+300%2C+300%2C+-5%2C+5%2C+-5%2C5%2C++-x+%2B+2%29\"\r\n" );
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document.write( "We see that it is not vertical. So we can proceed\r\n" );
document.write( "as usual:\r\n" );
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document.write( "We are to find an equation of the line containing \r\n" );
document.write( "the points (-1,3) and (4,-2)\r\n" );
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document.write( "Use the slope formula:\r\n" );
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document.write( "     y2 - y1\r\n" );
document.write( "m = —————————\r\n" );
document.write( "     x2 - x1\r\n" );
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document.write( "where (x1, y1) = (-1,3) and (x2, y2) = (4, -2)\r\n" );
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document.write( "    (-2) - (3)    -5      -5\r\n" );
document.write( "m = —————————— = ————— = ———— = -1\r\n" );
document.write( "    (4) - (-1)    4+1      5 \r\n" );
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document.write( "Now substitute in the point slope formula:\r\n" );
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document.write( "   y - y1 = m(x - x1)\r\n" );
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document.write( "   y - 3 = (-1)(x - (-1) )\r\n" );
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document.write( "   y - 3 = -(x + 1)\r\n" );
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document.write( "   y - 3 = -x - 1\r\n" );
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document.write( "       y = -x + 2\r\n" );
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document.write( "That's the equation in the slope-intercept\r\n" );
document.write( "form because we can compare it with\r\n" );
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document.write( "       y = mx + b\r\n" );
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document.write( "and see that its slope m is -1 and its\r\n" );
document.write( "y-intercept (0,b) is the point (0,2)\r\n" );
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document.write( "(2,-3) and (2,4) \r\n" );
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document.write( "We plot those two points and draw a line\r\n" );
document.write( "through them:\r\n" );
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document.write( "\"graph%28300%2C300%2C-6%2C6%2C-6%2C6%2C9999%28x-2%29%29\"\r\n" );
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document.write( "It is vertical, so we can't go the usual route.\r\n" );
document.write( "Since vertical lines are the only kind of lines\r\n" );
document.write( "which don't have slopes, there is no slope-intercept\r\n" );
document.write( "form.  But we can still write the equation.  It is \r\n" );
document.write( "simply this:\r\n" );
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document.write( "       x = 2\r\n" );
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document.write( "because every point on that line has x-coordinate 2.\r\n" );
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document.write( "So x = 2 tells the story of every point on the line,\r\n" );
document.write( "so that's all there is to the equation of that vertical\r\n" );
document.write( "line.\r\n" );
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document.write( "Edwin\r\n" );
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