document.write( "Question 79782: Find an equation of the line passing through each pair of points. Write the equation in the form Ax+By=C\r
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Algebra.Com's Answer #57238 by jim_thompson5910(35256)\"\" \"About 
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Solved by pluggable solver: Finding the Equation of a Line
First lets find the slope through the points (\"5\",\"-2\") and (\"3\",\"7\")
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\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: (\"x%5B1%5D\",\"y%5B1%5D\") is the first point (\"5\",\"-2\") and (\"x%5B2%5D\",\"y%5B2%5D\") is the second point (\"3\",\"7\"))
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\n" ); document.write( " \"m=%287--2%29%2F%283-5%29\" Plug in \"y%5B2%5D=7\",\"y%5B1%5D=-2\",\"x%5B2%5D=3\",\"x%5B1%5D=5\" (these are the coordinates of given points)
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\n" ); document.write( " \"m=+9%2F-2\" Subtract the terms in the numerator \"7--2\" to get \"9\". Subtract the terms in the denominator \"3-5\" to get \"-2\"
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\n" ); document.write( " \"m=-9%2F2\" Reduce
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\n" ); document.write( " So the slope is
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\n" ); document.write( " \"m=-9%2F2\"
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\n" ); document.write( "Now let's use the point-slope formula to find the equation of the line:
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\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 (\"x%5B1%5D\",\"y%5B1%5D\") is one of the given points
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\n" ); document.write( " So lets use the Point-Slope Formula to find the equation of the line
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\n" ); document.write( " \"y--2=%28-9%2F2%29%28x-5%29\" Plug in \"m=-9%2F2\", \"x%5B1%5D=5\", and \"y%5B1%5D=-2\" (these values are given)
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\n" ); document.write( " \"y%2B2=%28-9%2F2%29%28x-5%29\" Rewrite \"y--2\" as \"y%2B2\"
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\n" ); document.write( " \"y%2B2=%28-9%2F2%29x%2B%28-9%2F2%29%28-5%29\" Distribute \"-9%2F2\"
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\n" ); document.write( " \"y%2B2=%28-9%2F2%29x%2B45%2F2\" Multiply \"-9%2F2\" and \"-5\" to get \"45%2F2\"
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\n" ); document.write( " \"y=%28-9%2F2%29x%2B45%2F2-2\" Subtract \"2\" from both sides to isolate y
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\n" ); document.write( " \"y=%28-9%2F2%29x%2B41%2F2\" Combine like terms \"45%2F2\" and \"-2\" to get \"41%2F2\" (note: if you need help with combining fractions, check out this solver)
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\n" ); document.write( " Answer:
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\n" ); document.write( " So the equation of the line which goes through the points (\"5\",\"-2\") and (\"3\",\"7\") is:\"y=%28-9%2F2%29x%2B41%2F2\"
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\n" ); document.write( " The equation is now in \"y=mx%2Bb\" form (which is slope-intercept form) where the slope is \"m=-9%2F2\" and the y-intercept is \"b=41%2F2\"
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\n" ); document.write( " Notice if we graph the equation \"y=%28-9%2F2%29x%2B41%2F2\" and plot the points (\"5\",\"-2\") and (\"3\",\"7\"), we get this: (note: if you need help with graphing, check out this solver)
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\n" ); document.write( " Graph of \"y=%28-9%2F2%29x%2B41%2F2\" through the points (\"5\",\"-2\") and (\"3\",\"7\")
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\n" ); document.write( " Notice how the two points lie on the line. This graphically verifies our answer.
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\n" ); document.write( "\n" ); document.write( "Now to get it into standard form, add 4.5x to both sides\r
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\n" ); document.write( "\n" ); document.write( "\"y%2B4.5x=cross%28-4.5x%2B4.5x%29%2B20.5\"\r
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\n" ); document.write( "\n" ); document.write( "\"y%2B4.5x=20.5\"\r
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\n" ); document.write( "\n" ); document.write( "Now multiply both sides by 2\r
\n" ); document.write( "\n" ); document.write( "\"2%28y%2B4.5x%29=2%2820.5%29\"\r
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\n" ); document.write( "\n" ); document.write( "\"2y%2B9x=41\"\r
\n" ); document.write( "\n" ); document.write( "So it is now in standard form if we arrange x and y\r
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\n" ); document.write( "\n" ); document.write( "\"9x%2B2y=41\"
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\n" ); document.write( "\n" ); document.write( "where A=9, B=2, and C=41
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