document.write( "Question 112937This question is from textbook
\n" ); document.write( ": A line goes through the coordinate (3,4) and through (5,1). Find a line of the form y=ax+b. \n" ); document.write( "
Algebra.Com's Answer #82261 by jim_thompson5910(35256)\"\" \"About 
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First lets find the slope through the points (\"3\",\"4\") and (\"5\",\"1\")\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 (\"3\",\"4\") and is the second point (\"5\",\"1\"))\r
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\n" ); document.write( "\n" ); document.write( "\"m=%281-4%29%2F%285-3%29\" Plug in \"y%5B2%5D=1\",\"y%5B1%5D=4\",\"x%5B2%5D=5\",\"x%5B1%5D=3\" (these are the coordinates of given points)\r
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\n" ); document.write( "\n" ); document.write( "\"m=+-3%2F2\" Subtract the terms in the numerator \"1-4\" to get \"-3\". Subtract the terms in the denominator \"5-3\" to get \"2\"\r
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\n" ); document.write( "\n" ); document.write( "So the slope is\r
\n" ); document.write( "\n" ); document.write( "\"m=-3%2F2\"\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-4=%28-3%2F2%29%28x-3%29\" Plug in \"m=-3%2F2\", \"x%5B1%5D=3\", and \"y%5B1%5D=4\" (these values are given)\r
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\n" ); document.write( "\n" ); document.write( "\"y-4=%28-3%2F2%29x%2B%28-3%2F2%29%28-3%29\" Distribute \"-3%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "\"y-4=%28-3%2F2%29x%2B9%2F2\" Multiply \"-3%2F2\" and \"-3\" to get \"9%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "\"y=%28-3%2F2%29x%2B9%2F2%2B4\" Add \"4\" to both sides to isolate y\r
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\n" ); document.write( "\n" ); document.write( "\"y=%28-3%2F2%29x%2B17%2F2\" Combine like terms \"9%2F2\" and \"4\" to get \"17%2F2\" (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 (\"3\",\"4\") and (\"5\",\"1\") is:\"y=%28-3%2F2%29x%2B17%2F2\"\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=-3%2F2\" and the y-intercept is \"b=17%2F2\"\r
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\n" ); document.write( "\n" ); document.write( "Notice if we graph the equation \"y=%28-3%2F2%29x%2B17%2F2\" and plot the points (\"3\",\"4\") and (\"5\",\"1\"), 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=%28-3%2F2%29x%2B17%2F2\" through the points (\"3\",\"4\") and (\"5\",\"1\")\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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