document.write( "Question 85192: A line has the equation 2x – y = 3
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\n" ); document.write( " c. Graph all three lines on the same graph.
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Algebra.Com's Answer #61405 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
First convert \"2x-y+=+3\" 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)


\"2x-1y=3\" Start with the given equation


\"2x-1y-2x=3-2x\" Subtract 2x from both sides


\"-1y=-2x%2B3\" Simplify


\"%28-1y%29%2F%28-1%29=%28-2x%2B3%29%2F%28-1%29\" Divide both sides by -1 to isolate y


\"y+=+%28-2x%29%2F%28-1%29%2B%283%29%2F%28-1%29\" Break up the fraction on the right hand side


\"y+=+2x-3\" Reduce and simplify


The original equation \"2x-1y=3\" (standard form) is equivalent to \"y+=+2x-3\" (slope-intercept form)


The equation \"y+=+2x-3\" is in the form \"y=mx%2Bb\" where \"m=2\" is the slope and \"b=-3\" is the y intercept.



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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( " Since any two parallel lines have the same slope we know the slope of the unknown line is \"2\" (its from the slope of \"y=2%2Ax-3\" which is also \"2\").\n" ); document.write( "Also since the unknown line goes through (1,-2), 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%2B2=2%2A%28x-1%29\" Plug in \"m=2\", \"x%5B1%5D=1\", and \"y%5B1%5D=-2\"
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\n" ); document.write( " \"y%2B2=2%2Ax-%282%29%281%29\" Distribute \"2\"
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\n" ); document.write( " \"y%2B2=2%2Ax-2\" Multiply
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\n" ); document.write( " \"y=2%2Ax-2-2\"Subtract \"-2\" from both sides to isolate y
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\n" ); document.write( " \"y=2%2Ax-4\" Combine like terms
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\n" ); document.write( " So the equation of the line that is parallel to \"y=2%2Ax-3\" and goes through (\"1\",\"-2\") is \"y=2%2Ax-4\"
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\n" ); document.write( " So here are the graphs of the equations \"y=2%2Ax-3\" and \"y=2%2Ax-4\"
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\n" ); document.write( " graph of the given equation \"y=2%2Ax-3\" (red) and graph of the line \"y=2%2Ax-4\"(green) that is parallel to the given graph and goes through (\"1\",\"-2\")
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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%282%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%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=-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-3\").\n" ); document.write( "Also since the unknown line goes through (1,-2), 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%2B2=%28-1%2F2%29%2A%28x-1%29\" Plug in \"m=-1%2F2\", \"x%5B1%5D=1\", and \"y%5B1%5D=-2\"
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\n" ); document.write( " \"y%2B2=%28-1%2F2%29%2Ax%2B%281%2F2%29%281%29\" Distribute \"-1%2F2\"
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\n" ); document.write( " \"y%2B2=%28-1%2F2%29%2Ax%2B1%2F2\" Multiply
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\n" ); document.write( " \"y=%28-1%2F2%29%2Ax%2B1%2F2-2\"Subtract \"-2\" from both sides to isolate y
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\n" ); document.write( " \"y=%28-1%2F2%29%2Ax%2B1%2F2-4%2F2\" Make into equivalent fractions with equal denominators
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\n" ); document.write( " \"y=%28-1%2F2%29%2Ax-3%2F2\" Combine the fractions
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\n" ); document.write( " \"y=%28-1%2F2%29%2Ax-3%2F2\" Reduce any fractions
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\n" ); document.write( " So the equation of the line that is perpendicular to \"y=2%2Ax-3\" and goes through (\"1\",\"-2\") is \"y=%28-1%2F2%29%2Ax-3%2F2\"
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\n" ); document.write( " So here are the graphs of the equations \"y=2%2Ax-3\" and \"y=%28-1%2F2%29%2Ax-3%2F2\"
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\n" ); document.write( " graph of the given equation \"y=2%2Ax-3\" (red) and graph of the line \"y=%28-1%2F2%29%2Ax-3%2F2\"(green) that is perpendicular to the given graph and goes through (\"1\",\"-2\")
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\n" ); document.write( "So here are all three graphs\r
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\n" ); document.write( "\n" ); document.write( "\"+graph%28+500%2C+500%2C+-10%2C+10%2C+-10%2C+10%2C+2x-3%2C+2x-4%2C%28-1%2F2%29x-3%2F2%29+\" graph of \"2x-3\" (red), \"2x-4\" (green), and \"%28-1%2F2%29x-3%2F2%29\" (black)
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