document.write( "Question 455372: The question is: A river has a current of 3mph. A boat goes 35 miles upstream in the same time as it goes 45 miles downstream. Find the speed of the boat in still water?
\n" ); document.write( " I tried the following: d=rt let upstream = u and downstream =d so
\n" ); document.write( "45=3u+d - (35=3u+d) Please help i don't believe I'm doing this correctly.
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Algebra.Com's Answer #312647 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
The question is: A river has a current of 3mph. A boat goes 35 miles upstream in the same time as it goes 45 miles downstream. Find the speed of the boat in still water?
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\n" ); document.write( "downstream rate = b+3 mph where \"b\" is boat speed in still water
\n" ); document.write( "upstream rate = b-3 mph where \"b\" is boat speed in still water
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\n" ); document.write( "Upstream DATA:
\n" ); document.write( "distance = 35 miles ; rate = b-3 mph ; time = d/r = 35/(b-3) hrs.
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\n" ); document.write( "Dosnstream DATA:
\n" ); document.write( "distance = 45 miles ; rate = b+3 mph ; time = d/r = 45/(b+3)
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\n" ); document.write( "Equation:
\n" ); document.write( "time up = time down
\n" ); document.write( "35/(b-3) = 45/(b+3)
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\n" ); document.write( "35b + 105 = 45b - 135
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\n" ); document.write( "10b = 240
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\n" ); document.write( "b = 24 mph (speed of the boat in still water)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
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