document.write( "Question 143644: What is the equation of the line with slope 2/3 and passes through the midpoint of the segment joining points (-1, 6) and (-7, -4)? \n" ); document.write( "
Algebra.Com's Answer #104534 by jim_thompson5910(35256)\"\" \"About 
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First let's find the midpoint of the segment through (-1, 6) and (-7, -4)\r
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\n" ); document.write( "\n" ); document.write( "In order to find the midpoint between the points (-1, 6) and (-7, -4), we need to average each corresponding coordinate. In other words, we need to add up the corresponding coordinates and divide the sum by 2.\r
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\n" ); document.write( "\n" ); document.write( "So lets find the averages between the two points\r
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\n" ); document.write( "\n" ); document.write( "To find , average the x-coordinates between the two points\r
\n" ); document.write( "\n" ); document.write( "\"x%5Bmid%5D=%28-1%2B-7%29%2F2=%28-8%29%2F2=-4\"\r
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\n" ); document.write( "\n" ); document.write( "So the x-coordinate of the midpoint is -4 (i.e. x=-4)\r
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\n" ); document.write( "\n" ); document.write( "To find , average the y-coordinates between the two points\r
\n" ); document.write( "\n" ); document.write( "\"y%5Bmid%5D=%28+6%2B+-4%29%2F2=%282%29%2F2=1\"\r
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\n" ); document.write( "\n" ); document.write( "So the y-coordinate of the midpoint is 1 (i.e. y=1)\r
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\n" ); document.write( "\n" ); document.write( "So the midpoint is (-4,1)\r
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\n" ); document.write( "\n" ); document.write( "Now let's find the equation of the line with a slope of \"2%2F3\" and goes through the point (-4,1)\r
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\n" ); document.write( "\n" ); document.write( "If you want to find the equation of line with a given a slope of \"2%2F3\" which goes through the point (\"-4\",\"1\"), you can simply use the point-slope formula to find the equation:\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 the given point\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-1=%282%2F3%29%28x--4%29\" Plug in \"m=2%2F3\", \"x%5B1%5D=-4\", and \"y%5B1%5D=1\" (these values are given)\r
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\n" ); document.write( "\n" ); document.write( "\"y-1=%282%2F3%29%28x%2B4%29\" Rewrite \"x--4\" as \"x%2B4\"\r
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\n" ); document.write( "\n" ); document.write( "\"y-1=%282%2F3%29x%2B%282%2F3%29%284%29\" Distribute \"2%2F3\"\r
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\n" ); document.write( "\n" ); document.write( "\"y-1=%282%2F3%29x%2B8%2F3\" Multiply \"2%2F3\" and \"4\" to get \"8%2F3\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=%282%2F3%29x%2B8%2F3%2B1\" Add 1 to both sides to isolate y\r
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\n" ); document.write( "\n" ); document.write( "\"y=%282%2F3%29x%2B11%2F3\" Combine like terms \"8%2F3\" and \"1\" to get \"11%2F3\" (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 with a slope of \"2%2F3\" which goes through the point (\"-4\",\"1\") is:\r
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\n" ); document.write( "\n" ); document.write( "\"y=%282%2F3%29x%2B11%2F3\" which is now in \"y=mx%2Bb\" form where the slope is \"m=2%2F3\" and the y-intercept is \"b=11%2F3\"\r
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\n" ); document.write( "\n" ); document.write( "Notice if we graph the equation \"y=%282%2F3%29x%2B11%2F3\" and plot the point (\"-4\",\"1\"), we get (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=%282%2F3%29x%2B11%2F3\" through the point (\"-4\",\"1\")\r
\n" ); document.write( "\n" ); document.write( "and we can see that the point lies on the line. Since we know the equation has a slope of \"2%2F3\" and goes through the point (\"-4\",\"1\"), this verifies our answer.
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