document.write( "Question 1144501: Mike and his brothers can row a boat 18 km per hour in still water. It takes them as long to row 14 km downstream and 10 km upstream. Find the speed of the stream. \n" ); document.write( "

Algebra.Com's Answer #765645 by ikleyn(52803) $\"\"$ $\"About$

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document.write( "Let x be the speed of the stream\r\n" );
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document.write( "Then  the speed rowing downstream is  (18+x) km/h, \r\n" );
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document.write( "while the speed rowing   upstream is  (18-x) km/h.\r\n" );
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document.write( "The time rowing 14 kilometers downstream is    hours;\r\n" );
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document.write( "the time rowing 10 kilometers  upstream is    hours.\r\n" );
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document.write( "It gives you the equation\r\n" );
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document.write( "      = .\r\n" );
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document.write( "To solve it, multiply both sides by (18+x)*(18-x).  You will get\r\n" );
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document.write( "    14*(18-x) = 10*(18+x)\r\n" );
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document.write( "    14*18 - 14x = 10*18 + 10x\r\n" );
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document.write( "     14*18 - 10*18 = 10x + 14x\r\n" );
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document.write( "     4*18          = 24x\r\n" );
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document.write( "     x             =  = 3.\r\n" );
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document.write( "ANSWER.  The rate of the stream is 3 kilometers per hour.\r\n" );
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