document.write( "Question 102629: I want to double check my answer regarding the following math problem:\r
\n" ); document.write( "\n" ); document.write( "Write an equation in the slope intercept form if possible: for the line which is at (0,-3) and is perpendicular to x - 2y = 7\r
\n" ); document.write( "\n" ); document.write( "My equation is:
\n" ); document.write( "x-2y=7\r
\n" ); document.write( "\n" ); document.write( "x=2y+7\r
\n" ); document.write( "\n" ); document.write( "2y+y=x\r
\n" ); document.write( "\n" ); document.write( "2y/2 = x/2 - 7/2\r
\n" ); document.write( "\n" ); document.write( "Y intercept is x/2 - 7/2\r
\n" ); document.write( "\n" ); document.write( "Now I'm lost as far as the slope is concerned\r
\n" ); document.write( "\n" ); document.write( "Please help\r
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Algebra.Com's Answer #74649 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "\n" ); document.write( "First convert the standard equation \"x-2y=7\" into slope intercept form\r
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Solved by pluggable solver: Converting Linear Equations in Standard form to Slope-Intercept Form (and vice versa)
Convert from standard form (Ax+By = C) to slope-intercept form (y = mx+b)


\"1x-2y=7\" Start with the given equation


\"1x-2y-1x=7-1x\" Subtract 1x from both sides


\"-2y=-1x%2B7\" Simplify


\"%28-2y%29%2F%28-2%29=%28-1x%2B7%29%2F%28-2%29\" Divide both sides by -2 to isolate y


\"y+=+%28-1x%29%2F%28-2%29%2B%287%29%2F%28-2%29\" Break up the fraction on the right hand side


\"y+=+%281%2F2%29x-7%2F2\" Reduce and simplify


The original equation \"1x-2y=7\" (standard form) is equivalent to \"y+=+%281%2F2%29x-7%2F2\" (slope-intercept form)


The equation \"y+=+%281%2F2%29x-7%2F2\" is in the form \"y=mx%2Bb\" where \"m=1%2F2\" is the slope and \"b=-7%2F2\" is the y intercept.



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\n" ); document.write( "\n" ); document.write( "Now let's find the equation of the line that is perpendicular to \"y=%281%2F2%29x-7%2F2\" which goes through (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 \"1%2F2\", 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%281%2F2%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%282%2F1%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=-2%2F1\" Multiply the fractions.
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\n" ); document.write( " So the perpendicular slope is \"-2\"
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\n" ); document.write( " So now we know the slope of the unknown line is \"-2\" (its the negative reciprocal of \"1%2F2\" from the line \"y=%281%2F2%29%2Ax-7%2F2\").\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%2B3=-2%2A%28x-0%29\" Plug in \"m=-2\", \"x%5B1%5D=0\", and \"y%5B1%5D=-3\"
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\n" ); document.write( " \"y%2B3=-2%2Ax%2B%282%29%280%29\" Distribute \"-2\"
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\n" ); document.write( " \"y%2B3=-2%2Ax-0\" Multiply
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\n" ); document.write( " \"y=-2%2Ax-0-3\"Subtract \"-3\" from both sides to isolate y
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\n" ); document.write( " \"y=-2%2Ax-3\" Combine like terms
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\n" ); document.write( " So the equation of the line that is perpendicular to \"y=%281%2F2%29%2Ax-7%2F2\" and goes through (\"0\",\"-3\") is \"y=-2%2Ax-3\"
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\n" ); document.write( " So here are the graphs of the equations \"y=%281%2F2%29%2Ax-7%2F2\" and \"y=-2%2Ax-3\"
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\n" ); document.write( " graph of the given equation \"y=%281%2F2%29%2Ax-7%2F2\" (red) and graph of the line \"y=-2%2Ax-3\"(green) that is perpendicular to the given graph and goes through (\"0\",\"-3\")
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