document.write( "Question 478245: What is an equation of the line perpendicular to the graph of y = -2x + 5 that passes through the point at (4, 7)? Write your answer in slope intercept form. \n" ); document.write( "
Algebra.Com's Answer #327690 by MathLover1(20850)\"\" \"About 
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Solved by pluggable solver: Finding the Equation of a Line Parallel or Perpendicular to a Given Line

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\n" ); document.write( " Remember, any two perpendicular lines are negative reciprocals of each other. So if you're given the slope of \"-2\", you can find the perpendicular slope by this formula:
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\n" ); document.write( " \"m%5Bp%5D=-1%2Fm\" where \"m%5Bp%5D\" is the perpendicular slope
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\n" ); document.write( " \"m%5Bp%5D=-1%2F%28-2%2F1%29\" So plug in the given slope to find the perpendicular slope
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\n" ); document.write( " \"m%5Bp%5D=%28-1%2F1%29%281%2F-2%29\" When you divide fractions, you multiply the first fraction (which is really \"1%2F1\") by the reciprocal of the second
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\n" ); document.write( " \"m%5Bp%5D=1%2F2\" Multiply the fractions.
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\n" ); document.write( " So the perpendicular slope is \"1%2F2\"
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\n" ); document.write( " So now we know the slope of the unknown line is \"1%2F2\" (its the negative reciprocal of \"-2\" from the line \"y=-2%2Ax%2B5\").\n" ); document.write( "Also since the unknown line goes through (4,7), we can find the equation by plugging in this info into the point-slope formula
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\n" ); document.write( " Point-Slope Formula:
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\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 the given point
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\n" ); document.write( " \"y-7=%281%2F2%29%2A%28x-4%29\" Plug in \"m=1%2F2\", \"x%5B1%5D=4\", and \"y%5B1%5D=7\"
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\n" ); document.write( " \"y-7=%281%2F2%29%2Ax-%281%2F2%29%284%29\" Distribute \"1%2F2\"
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\n" ); document.write( " \"y-7=%281%2F2%29%2Ax-4%2F2\" Multiply
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\n" ); document.write( " \"y=%281%2F2%29%2Ax-4%2F2%2B7\"Add \"7\" to both sides to isolate y
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\n" ); document.write( " \"y=%281%2F2%29%2Ax-4%2F2%2B14%2F2\" Make into equivalent fractions with equal denominators
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\n" ); document.write( " \"y=%281%2F2%29%2Ax%2B10%2F2\" Combine the fractions
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\n" ); document.write( " \"y=%281%2F2%29%2Ax%2B5\" Reduce any fractions
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\n" ); document.write( " So the equation of the line that is perpendicular to \"y=-2%2Ax%2B5\" and goes through (\"4\",\"7\") is \"y=%281%2F2%29%2Ax%2B5\"
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\n" ); document.write( " So here are the graphs of the equations \"y=-2%2Ax%2B5\" and \"y=%281%2F2%29%2Ax%2B5\"
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\n" ); document.write( " graph of the given equation \"y=-2%2Ax%2B5\" (red) and graph of the line \"y=%281%2F2%29%2Ax%2B5\"(green) that is perpendicular to the given graph and goes through (\"4\",\"7\")
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