document.write( "Question 427544: the speed of a stream is 3 mph. A boat travels 3 miles upstream in the same time it takes to travel 9 miles downstream. What is the speed of the boat in still water?
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Algebra.Com's Answer #551636 by richwmiller(17219)\"\" \"About 
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r*t=d
\n" ); document.write( "(r-3)*t=3
\n" ); document.write( "(r-3*t=3
\n" ); document.write( "r*t-3*t=3\r
\n" ); document.write( "\n" ); document.write( "(r+3)*t=9
\n" ); document.write( "r*t+3*t=9
\n" ); document.write( "r*t-3*t=3
\n" ); document.write( "add
\n" ); document.write( "2r*t=12
\n" ); document.write( "r*t=12/2
\n" ); document.write( "r*t=6
\n" ); document.write( "ok
\n" ); document.write( "r*t-3*t=3
\n" ); document.write( "6-3*t=3
\n" ); document.write( "6-3=3*t
\n" ); document.write( "3=3*t
\n" ); document.write( "3/3=t
\n" ); document.write( "1=t
\n" ); document.write( "t=1 hour
\n" ); document.write( "r*1=6
\n" ); document.write( "r=6/1
\n" ); document.write( "r=6 mph
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\n" ); document.write( "(r+c)*t=9
\n" ); document.write( "(6+3)*1=9
\n" ); document.write( "(9)*1=9
\n" ); document.write( "9=9\r
\n" ); document.write( "\n" ); document.write( "(r-c)*t=3
\n" ); document.write( "(6-c)*t=3
\n" ); document.write( "(6-3)*1=3
\n" ); document.write( "3*1=3
\n" ); document.write( "3=3
\n" ); document.write( "ok
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