document.write( "Question 142827: find an equation of the line containing (-1,6) and (0,-3) and write the result in slope intercept form \n" ); document.write( "
Algebra.Com's Answer #103913 by jim_thompson5910(35256)\"\" \"About 
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First lets find the slope through the points (\"-1\",\"6\") and (\"0\",\"-3\")\r
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\n" ); document.write( "\n" ); document.write( "\"m=%28y%5B2%5D-y%5B1%5D%29%2F%28x%5B2%5D-x%5B1%5D%29\" Start with the slope formula (note: is the first point (\"-1\",\"6\") and is the second point (\"0\",\"-3\"))\r
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\n" ); document.write( "\n" ); document.write( "\"m=%28-3-6%29%2F%280--1%29\" Plug in \"y%5B2%5D=-3\",\"y%5B1%5D=6\",\"x%5B2%5D=0\",\"x%5B1%5D=-1\" (these are the coordinates of given points)\r
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\n" ); document.write( "\n" ); document.write( "\"m=+-9%2F1\" Subtract the terms in the numerator \"-3-6\" to get \"-9\". Subtract the terms in the denominator \"0--1\" to get \"1\"\r
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\n" ); document.write( "\n" ); document.write( "\"m=-9\" Reduce\r
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\n" ); document.write( "\n" ); document.write( "So the slope is\r
\n" ); document.write( "\n" ); document.write( "\"m=-9\"\r
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\n" ); document.write( "\n" ); document.write( "Now let's use the point-slope formula to find the equation of the line:\r
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\n" ); document.write( "\n" ); document.write( "------Point-Slope Formula------
\n" ); document.write( "\"y-y%5B1%5D=m%28x-x%5B1%5D%29\" where \"m\" is the slope, and is one of the given points\r
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\n" ); document.write( "\n" ); document.write( "So lets use the Point-Slope Formula to find the equation of the line\r
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\n" ); document.write( "\n" ); document.write( "\"y-6=%28-9%29%28x--1%29\" Plug in \"m=-9\", \"x%5B1%5D=-1\", and \"y%5B1%5D=6\" (these values are given)\r
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\n" ); document.write( "\n" ); document.write( "\"y-6=%28-9%29%28x%2B1%29\" Rewrite \"x--1\" as \"x%2B1\"\r
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\n" ); document.write( "\n" ); document.write( "\"y-6=-9x%2B%28-9%29%281%29\" Distribute \"-9\"\r
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\n" ); document.write( "\n" ); document.write( "\"y-6=-9x-9\" Multiply \"-9\" and \"1\" to get \"-9\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=-9x-9%2B6\" Add \"6\" to both sides to isolate y\r
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\n" ); document.write( "\n" ); document.write( "\"y=-9x-3\" Combine like terms \"-9\" and \"6\" to get \"-3\" (note: if you need help with combining fractions, check out this solver)\r
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\n" ); document.write( "\n" ); document.write( "Answer:\r
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\n" ); document.write( "\n" ); document.write( "So the equation of the line which goes through the points (\"-1\",\"6\") and (\"0\",\"-3\") is:\"y=-9x-3\"\r
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\n" ); document.write( "\n" ); document.write( "The equation is now in \"y=mx%2Bb\" form (which is slope-intercept form) where the slope is \"m=-9\" and the y-intercept is \"b=-3\"\r
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\n" ); document.write( "\n" ); document.write( "Notice if we graph the equation \"y=-9x-3\" and plot the points (\"-1\",\"6\") and (\"0\",\"-3\"), we get this: (note: if you need help with graphing, check out this solver)\r
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\n" ); document.write( "\n" ); document.write( " Graph of \"y=-9x-3\" through the points (\"-1\",\"6\") and (\"0\",\"-3\")\r
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\n" ); document.write( "\n" ); document.write( "Notice how the two points lie on the line. This graphically verifies our answer.
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