document.write( "Question 991065: A boat takes 8 hours to travel 80 miles upstream and 5 hours to return to its starting point .find the speed of the boat in still water and the speed of the current \n" ); document.write( "
Algebra.Com's Answer #611049 by lwsshak3(11628)\"\" \"About 
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A boat takes 8 hours to travel 80 miles upstream and 5 hours to return to its starting point .find the speed of the boat in still water and the speed of the current\r
\n" ); document.write( "\n" ); document.write( "let x=speed of boat in still water
\n" ); document.write( "let c=speed of current
\n" ); document.write( "(x+c)=speed of boat downstream
\n" ); document.write( "(x-c)=speed of boat upstream
\n" ); document.write( "travel time*speed=distance\r
\n" ); document.write( "\n" ); document.write( "8(x-c)=80
\n" ); document.write( "5(x+c)=80\r
\n" ); document.write( "\n" ); document.write( "8x-8c=80
\n" ); document.write( "5x+5c=80\r
\n" ); document.write( "\n" ); document.write( "40x-40c=400
\n" ); document.write( "40x+40c=640
\n" ); document.write( "80x=1040
\n" ); document.write( "x=13
\n" ); document.write( "x-c=10
\n" ); document.write( "c=3
\n" ); document.write( "speed of boat in still water=13 mph
\n" ); document.write( "speed of current=3 mph
\n" ); document.write( " \n" ); document.write( "
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