document.write( "Question 146191: Please write an equation of the line through (-5,4) and perpendicular to the line 5x + 4y = 24. Thank You \n" ); document.write( "
Algebra.Com's Answer #106745 by jim_thompson5910(35256)\"\" \"About 
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\n" ); document.write( "\"5x+%2B+4y+=+24\" Start with the given equation.\r
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\n" ); document.write( "\n" ); document.write( "\"4y=24-5x\" Subtract \"5x\" from both sides.\r
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\n" ); document.write( "\n" ); document.write( "\"y=%2824-5x%29%2F%284%29\" Divide both sides by \"4\" to isolate \"y\".\r
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\n" ); document.write( "\n" ); document.write( "\"y=-%285%2F4%29x%2B6\" Rearrange the terms and simplify.\r
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\n" ); document.write( "\n" ); document.write( "We can see that the equation \"y=-%285%2F4%29x%2B6\" has a slope \"m=-5%2F4\" and a y-intercept \"b=6\".\r
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\n" ); document.write( "\n" ); document.write( "Now to find the slope of the perpendicular line, simply flip the slope \"m=-5%2F4\" to get \"m=-4%2F5\". Now change the sign to get \"m=4%2F5\". So the perpendicular slope is \"m=4%2F5\".\r
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\n" ); document.write( "\n" ); document.write( "Now let's use the point slope formula to find the equation of the perpendicular line by plugging in the slope \"m=-5%2F4\" and the coordinates of the given point .\r
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\n" ); document.write( "\n" ); document.write( "\"y-y%5B1%5D=m%28x-x%5B1%5D%29\" Start with the point slope formula\r
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\n" ); document.write( "\n" ); document.write( "\"y-4=%284%2F5%29%28x--5%29\" Plug in \"m=4%2F5\", \"x%5B1%5D=-5\", and \"y%5B1%5D=4\"\r
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\n" ); document.write( "\n" ); document.write( "\"y-4=%284%2F5%29%28x%2B5%29\" Rewrite \"x--5\" as \"x%2B5\"\r
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\n" ); document.write( "\n" ); document.write( "\"y-4=%284%2F5%29x%2B%284%2F5%29%285%29\" Distribute\r
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\n" ); document.write( "\n" ); document.write( "\"y-4=%284%2F5%29x%2B4\" Multiply\r
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\n" ); document.write( "\n" ); document.write( "\"y=%284%2F5%29x%2B4%2B4\" Add 4 to both sides. \r
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\n" ); document.write( "\n" ); document.write( "\"y=%284%2F5%29x%2B8\" Combine like terms. \r
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\n" ); document.write( "\n" ); document.write( "So the equation of the line perpendicular to \"5x+%2B+4y+=+24\" that goes through the point is \"y=%284%2F5%29x%2B8\".\r
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\n" ); document.write( "\n" ); document.write( "Here's a graph to visually verify our answer:\r
\n" ); document.write( "\n" ); document.write( "Graph of the original equation \"y=-%285%2F4%29x%2B6\" (red) and the perpendicular line \"y=%284%2F5%29x%2B8\" (green) through the point .
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