document.write( "Question 359510: Debbie traveled by boat 5 miles upstream to
\n" ); document.write( "fish in her favorite spot. Because of the 4-mph current, it
\n" ); document.write( "took her 20 minutes longer to get there than to return. How
\n" ); document.write( "fast will her boat go in still water? \n" ); document.write( "
Algebra.Com's Answer #256506 by mananth(16946)\"\" \"About 
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Debbie traveled by boat 5 miles upstream to
\n" ); document.write( "fish in her favorite spot. Because of the 4-mph current, it
\n" ); document.write( "took her 20 minutes longer to get there than to return. How
\n" ); document.write( "fast will her boat go in still water?
\n" ); document.write( "...
\n" ); document.write( "let still water speed = x mph
\n" ); document.write( "downstream speed = x+4 mph
\n" ); document.write( "upstream speed = x-4 mph
\n" ); document.write( "time upstream = 5/(x-4)
\n" ); document.write( "time downstream = x/(x+4)
\n" ); document.write( "time upstream - time donstream = 1/3 hours
\n" ); document.write( "5/(x-4)-5/(x+4)=1/3
\n" ); document.write( "5(x+4)-5(x-4)/(x+4)(x-4)=1/3
\n" ); document.write( "5x+20-5x+20=(x+4)(x-4)/3
\n" ); document.write( "40=(x^2-16)/3
\n" ); document.write( "120 = x^2-16
\n" ); document.write( "x^2=136
\n" ); document.write( "x = 11.66 mph
\n" ); document.write( "...
\n" ); document.write( "m.ananth@hotmail.ca \n" ); document.write( "
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