document.write( "Question 506997: Write the equation of a line in slope-intercept form passing through (2, 7) and (-2, 9). \n" ); document.write( "
Algebra.Com's Answer #340290 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( "First let's find the slope of the line through the points and \r
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\n" ); document.write( "\n" ); document.write( "Note: is the first point . So this means that \"x%5B1%5D=2\" and \"y%5B1%5D=7\".\r
\n" ); document.write( "\n" ); document.write( "Also, is the second point . So this means that \"x%5B2%5D=-2\" and \"y%5B2%5D=9\".\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.\r
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\n" ); document.write( "\n" ); document.write( "\"m=%289-7%29%2F%28-2-2%29\" Plug in \"y%5B2%5D=9\", \"y%5B1%5D=7\", \"x%5B2%5D=-2\", and \"x%5B1%5D=2\"\r
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\n" ); document.write( "\n" ); document.write( "\"m=%282%29%2F%28-2-2%29\" Subtract \"7\" from \"9\" to get \"2\"\r
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\n" ); document.write( "\n" ); document.write( "\"m=%282%29%2F%28-4%29\" Subtract \"2\" from \"-2\" to get \"-4\"\r
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\n" ); document.write( "\n" ); document.write( "\"m=-1%2F2\" Reduce\r
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\n" ); document.write( "\n" ); document.write( "So the slope of the line that goes through the points and is \"m=-1%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "Now let's use the point slope formula:\r
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\n" ); document.write( "\n" ); document.write( "\"y-y%5B1%5D=m%28x-x%5B1%5D%29\" Start with the point slope formula\r
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\n" ); document.write( "\n" ); document.write( "\"y-7=%28-1%2F2%29%28x-2%29\" Plug in \"m=-1%2F2\", \"x%5B1%5D=2\", and \"y%5B1%5D=7\"\r
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\n" ); document.write( "\n" ); document.write( "\"y-7=%28-1%2F2%29x%2B%28-1%2F2%29%28-2%29\" Distribute\r
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\n" ); document.write( "\n" ); document.write( "\"y-7=%28-1%2F2%29x%2B1\" Multiply\r
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\n" ); document.write( "\n" ); document.write( "\"y=%28-1%2F2%29x%2B1%2B7\" Add 7 to both sides. \r
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\n" ); document.write( "\n" ); document.write( "\"y=%28-1%2F2%29x%2B8\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "So the equation that goes through the points and is \"y=%28-1%2F2%29x%2B8\"\r
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\n" ); document.write( "\n" ); document.write( " Notice how the graph of \"y=%28-1%2F2%29x%2B8\" goes through the points and . So this visually verifies our answer.\r
\n" ); document.write( "\n" ); document.write( " Graph of \"y=%28-1%2F2%29x%2B8\" through the points and \r
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\n" ); document.write( "\n" ); document.write( "Let me know if you need more help or if you need me to explain a step in more detail.
\n" ); document.write( "Feel free to email me at jim_thompson5910@hotmail.com
\n" ); document.write( "or you can visit my website here: http://www.freewebs.com/jimthompson5910/home.html\r
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\n" ); document.write( "\n" ); document.write( "Thanks,\r
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\n" ); document.write( "\n" ); document.write( "Jim
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