document.write( "Question 67179This question is from textbook Algebra 1
\n" ); document.write( ": It took 3 hours to row a boat 18 km against the current, The return trip with the current took 1 1/2 hours. Find the speed of the rowboat in still water.
\n" ); document.write( "THANK YOU! \n" ); document.write( "
Algebra.Com's Answer #47862 by ankor@dixie-net.com(22740)\"\" \"About 
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It took 3 hours to row a boat 18 km against the current, The return trip with the current took 1 1/2 hours. Find the speed of the rowboat in still water.
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\n" ); document.write( "Let s = boat speed in still water
\n" ); document.write( "Let c = current speed:
\n" ); document.write( ":
\n" ); document.write( "Speed with the current: (s+c)
\n" ); document.write( "Speed against the current: (s-c)
\n" ); document.write( ":
\n" ); document.write( "Dist = time * speed:
\n" ); document.write( ":
\n" ); document.write( "3(s - c) = 18
\n" ); document.write( "Simplify divide both sides by 3
\n" ); document.write( "s - c = 6
\n" ); document.write( ":
\n" ); document.write( "1.5(s + c) = 18
\n" ); document.write( "Simplify divide both sides by 1.5
\n" ); document.write( "s + c = 12
\n" ); document.write( ":
\n" ); document.write( "Add these equations and eliminate c
\n" ); document.write( "s - c = 6
\n" ); document.write( "s + c = 12
\n" ); document.write( "----------- add
\n" ); document.write( "2s + 0 = 18
\n" ); document.write( "2s = 18
\n" ); document.write( "s = 9 mph is the speed in still water
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\n" ); document.write( ":
\n" ); document.write( "Find the current to check our solution:
\n" ); document.write( "9 + c = 12
\n" ); document.write( "c = 3 mph
\n" ); document.write( ":
\n" ); document.write( "3(9-3) = 18
\n" ); document.write( "1.5(9+3) = 18
\n" ); document.write( "1.5(s+c) = 18 \n" ); document.write( "
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