document.write( "Question 113925: Find the equation for the line with y-intercept 3 that is perpendicular to the line: y=2/3x-4 Possible answers: A) 2y=6-3x; B) 2y=3x+6; C) 3y=9-2x; D) 3y=2x+9 \n" ); document.write( "
Algebra.Com's Answer #82904 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
Remember if a line has the y-intercept 3, then it goes through the point (0,3)\r
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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%2F3\", 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%282%2F3%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%283%2F2%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=-3%2F2\" Multiply the fractions.
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\n" ); document.write( " So the perpendicular slope is \"-3%2F2\"
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\n" ); document.write( " So now we know the slope of the unknown line is \"-3%2F2\" (its the negative reciprocal of \"2%2F3\" from the line \"y=%282%2F3%29%2Ax-4\").\n" ); document.write( "Also since the unknown line goes through (0,3), 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-3=%28-3%2F2%29%2A%28x-0%29\" Plug in \"m=-3%2F2\", \"x%5B1%5D=0\", and \"y%5B1%5D=3\"
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\n" ); document.write( " \"y-3=%28-3%2F2%29%2Ax%2B%283%2F2%29%280%29\" Distribute \"-3%2F2\"
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\n" ); document.write( " \"y-3=%28-3%2F2%29%2Ax-0%2F2\" Multiply
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\n" ); document.write( " \"y=%28-3%2F2%29%2Ax-0%2F2%2B3\"Add \"3\" to both sides to isolate y
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\n" ); document.write( " \"y=%28-3%2F2%29%2Ax-0%2F2%2B6%2F2\" Make into equivalent fractions with equal denominators
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\n" ); document.write( " \"y=%28-3%2F2%29%2Ax%2B6%2F2\" Combine the fractions
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\n" ); document.write( " \"y=%28-3%2F2%29%2Ax%2B3\" Reduce any fractions
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\n" ); document.write( " So the equation of the line that is perpendicular to \"y=%282%2F3%29%2Ax-4\" and goes through (\"0\",\"3\") is \"y=%28-3%2F2%29%2Ax%2B3\"
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\n" ); document.write( " So here are the graphs of the equations \"y=%282%2F3%29%2Ax-4\" and \"y=%28-3%2F2%29%2Ax%2B3\"
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\n" ); document.write( " graph of the given equation \"y=%282%2F3%29%2Ax-4\" (red) and graph of the line \"y=%28-3%2F2%29%2Ax%2B3\"(green) that is perpendicular to the given graph and goes through (\"0\",\"3\")
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\n" ); document.write( "\n" ); document.write( "So if we multiply both sides of \"y=%28-3%2F2%29x%2B3\" by 2 we get \"2y=6-3x\". So the answer is A)
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