document.write( "Question 1100406: Find the distance from point A(−14, 5) to the line −x+2y = 14. Round your answer to the nearest tenth. \n" ); document.write( "
Algebra.Com's Answer #714883 by ikleyn(52781)\"\" \"About 
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\n" ); document.write( "There is a beatiful formula to find the distance from the given point to the given straight line in a coordinate plane.\r
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document.write( "    Let the straight line in a coordinate plane is defined in terms of its linear equation \r\n" );
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document.write( "        a*x + b*y + c = 0,\r\n" );
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document.write( "    where  a,  b and  c  are real numbers,  and let  P = P(\"x%5B0%5D\",\"y%5B0%5D\")  is the point in the coordinate plane \r\n" );
document.write( "    with the coordinates  \"x%5B0%5D\",  \"y%5B0%5D\".  Then the distance from the point  P  to the straight line is equal to\r\n" );
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document.write( "        d = \"abs%28a%2Ax%5B0%5D+%2B+b%2Ay%5B0%5D+%2B+c%29%2Fsqrt%28a%5E2+%2B+b%5E2%29\".\r\n" );
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\n" ); document.write( "\n" ); document.write( "See the lesson  The distance from a point to a straight line in a coordinate plane  in this site.\r
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\n" ); document.write( "\n" ); document.write( "So, in your case  a= -1,  b= 2,  c= -14   (after moving  \"c\"  from the righ side to the left),  \"x%5B0%5D\"= -14,  \"y%5B0%5D\"= 5.\r
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\n" ); document.write( "\n" ); document.write( "Substituting to the formula gives you the distance\r
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\n" ); document.write( "\n" ); document.write( " d = \"abs%28%28-1%29%2A%28-14%29+%2B+2%2A5+-14%29%2Fsqrt%28%28-1%29%5E2%2B2%5E2%29\" = \"abs%2814%2B10-14%29%2Fsqrt%281+%2B+4%29\" = \"10%2Fsqrt%285%29\" = \"%2810%2Asqrt%285%29%29%2F5%29\" = \"2%2Asqrt%285%29\" = 4.5 (approximately; rounded to the nearest tenth).\r
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\n" ); document.write( "\n" ); document.write( "Solved.\r
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\n" ); document.write( "\n" ); document.write( "Again,  for the proof of the formula and other details look into the above referred lesson.\r
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