document.write( "Question 880553: Julie and Eric row their boat (at a constant speed) 63 miles downstream for 7 hours, helped by the current. Rowing at the same rate, the trip back against the current takes 9 hours. Find the rate of current \n" ); document.write( "

Algebra.Com's Answer #531556 by lwsshak3(11628) $\"\"$ $\"About$

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Julie and Eric row their boat (at a constant speed) 63 miles downstream for 7 hours, helped by the current. Rowing at the same rate, the trip back against the current takes 9 hours. Find the rate of current
\n" ); document.write( "***
\n" ); document.write( "let x=constant speed of boat
\n" ); document.write( "let c=speed of current
\n" ); document.write( "x+c=speed of boat traveling with the current
\n" ); document.write( "x-c=speed of boat traveling against the current
\n" ); document.write( "travel time=distance/speed
\n" ); document.write( "..
\n" ); document.write( " $\"63%2F%28x%2Bc%29=7\"$
\n" ); document.write( " $\"63%2F%28x-c%29=9\"$
\n" ); document.write( "..
\n" ); document.write( "7x+7c=63
\n" ); document.write( "9x-9c=63
\n" ); document.write( "..
\n" ); document.write( "63x+63c=567 (mult. by 9)
\n" ); document.write( "63x-63c=441 (mult. by 7)
\n" ); document.write( "subtract:
\n" ); document.write( "126c=126
\n" ); document.write( "c=1
\n" ); document.write( "rate of current=1 mph \n" ); document.write( "

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