document.write( "Question 909912: Bryan's boat travels 15 km/h in still water.He motors 140 km downstream in the same time it takes to travel 35 km upstream. What is the speed of the river? \n" ); document.write( "

Algebra.Com's Answer #552124 by richwmiller(17219) $\"\"$ $\"About$

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r*t=d
\n" ); document.write( "(15-c)*t=35
\n" ); document.write( "15*t-c*t=35\r
\n" ); document.write( "\n" ); document.write( "(15+c)*t=140
\n" ); document.write( "15*t-c*t=35
\n" ); document.write( "15*t+c*t=140
\n" ); document.write( "add
\n" ); document.write( "30t=175
\n" ); document.write( "t=175/30
\n" ); document.write( "t=5.83333333 5 hr 50 minutes hr
\n" ); document.write( "15*5.83333333+c*5.83333333=140
\n" ); document.write( "87.5+c*5.83333333=140
\n" ); document.write( "c*5.83333333=52.5
\n" ); document.write( "c=52.5/5.83333333
\n" ); document.write( "c=9.0 mph current
\n" ); document.write( "check
\n" ); document.write( "(15+c)*t=140
\n" ); document.write( "(15+9)*5.83333333=140
\n" ); document.write( "(24)*5.83333333=140
\n" ); document.write( "140.0=140\r
\n" ); document.write( "\n" ); document.write( "(15-c)*t=35
\n" ); document.write( "(15-9)*5.83333333=35
\n" ); document.write( "(6)*5.83333333=35
\n" ); document.write( "35.0=35
\n" ); document.write( "ok
\n" ); document.write( " \n" ); document.write( "

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