document.write( "Question 1170886: An athlete plans to row upstream a distance of 6 km and then return to his starting
\n" ); document.write( "point downstream in a total time of 4 hours. If the speed of the current is 2 km/h, what is the
\n" ); document.write( "rowing speed of the athlete in still water?
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Algebra.Com's Answer #795765 by ikleyn(52814)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "An athlete \"highlight%28cross%28plans_to%29%29\" rows upstream a distance of 6 km and then returns to his starting
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\n" ); document.write( "\n" ); document.write( "            Notice that in your formulation  I  EXCLUDED  the  UNNECESSARY  words,  to which  THERE  IS  NO  PLACE \r
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document.write( "Let x be the athlete' speed in still water.\r\n" );
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document.write( "Then his (or her) speed downstream is (x+2) miles per hour and the time rowing downstream is  \"6%2F%28x%2B2%29\"  hours;\r\n" );
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document.write( "while         the speed   upstream is (x-2) miles per hour and the time rowing   upstream is  \"6%2F%28x-2%29\"  hours.\r\n" );
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document.write( "The total time equation is\r\n" );
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document.write( "    \"6%2F%28x%2B2%29\" + \"6%2F%28x-2%29\" = 4 hours.\r\n" );
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document.write( "If you want to solve it formally, you should reduce it to a quadratic equation and then\r\n" );
document.write( "solve it using the quadratic formula or by factoring.\r\n" );
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document.write( "Fortunately, the solution/(the answer) is clearly seen right from the equation: it is  x= 4 miles per hour.    ANSWER\r\n" );
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document.write( "Indeed,  \"6%2F%284%2B2%29\" + \"6%2F%284-2%29\" = \"6%2F6\" + \"6%2F2\" = 1 + 3 = 4 hours,  so my answer is correct.\r\n" );
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\n" ); document.write( "\n" ); document.write( "It is a typical and standard Upstream and Downstream round trip word problem.\r
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\n" ); document.write( "\n" ); document.write( "You can find many similar fully solved problems on upstream and downstream round trips with detailed solutions in lessons \r
\n" ); document.write( "\n" ); document.write( "    - Wind and Current problems solvable by quadratic equations \r
\n" ); document.write( "\n" ); document.write( "in this site, where you will find other similar solved problems with detailed explanations.\r
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\n" ); document.write( "\n" ); document.write( "Read it attentively and learn how to solve this type of problems once and for all.\r
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\n" ); document.write( "\n" ); document.write( "Also,  you have this free of charge online textbook in ALGEBRA-I in this site\r
\n" ); document.write( "\n" ); document.write( "    - ALGEBRA-I - YOUR ONLINE TEXTBOOK.\r
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\n" ); document.write( "\n" ); document.write( "The referred lesson is the part of this textbook under the section \"Word problems\",  the topic \"Travel and Distance problems\".\r
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\n" ); document.write( "\n" ); document.write( "Save the link to this online textbook together with its description\r
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\n" ); document.write( "\n" ); document.write( "Free of charge online textbook in ALGEBRA-I
\n" ); document.write( "https://www.algebra.com/algebra/homework/quadratic/lessons/ALGEBRA-I-YOUR-ONLINE-TEXTBOOK.lesson\r
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