document.write( "Question 1208220: Runner A is initially 5.6 km west of a flagpole
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Algebra.Com's Answer #846504 by ikleyn(52798) $\"\"$ $\"About$

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\n" ); document.write( "Runner A is initially 5.6 km west of a flagpole and is running with a constant velocity of 8.4 km/h due east.
\n" ); document.write( "Runner B is initially 4.9 km east of the flagpole and is running with a constant velocity of 7.5 km/h due west.
\n" ); document.write( "How far are the runners from the flagpole when their paths cross?
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document.write( "Lat assume that the flag pole is the zero point on x-axis directed from west to east.\r\n" );
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document.write( "Then the coordinate of the 1st runner in time is  -5.6 + 8.4*t kilometers;\r\n" );
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document.write( "     the coordinate of the 2nd runner in time is   4.9 - 7.5*t kilometers, \r\n" );
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document.write( "where t is the time from the start, in hours.\r\n" );
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document.write( "The runners are in the crossing point when\r\n" );
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document.write( "    -5.6 + 8.4t = 4.9 - 7.5t.\r\n" );
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document.write( "Simplify this equation and find t\r\n" );
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document.write( "    8.4t + 7.5t = 4.9 + 5.6\r\n" );
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document.write( "        15.9t   =   10.5\r\n" );
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document.write( "            t   =   10.5/15.9 = 0.660377358 of an hour.\r\n" );
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document.write( "The coordinate of the crossing point is  x = -5.6 + 8.4*0.660377358 = -0.052830193 kilometers,  \r\n" );
document.write( "or 52.83 meters west from the flag pole.   The numbers are approximate.\r\n" );
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