document.write( "Question 433314: Nancy traveled 6 miles upstream to do some fly fishing. It took her 20 minutes longer to get there than to return. If the current in the river is 2 miles per hour, then how fast will her boat go in still water. \n" ); document.write( "
Algebra.Com's Answer #300382 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
Nancy traveled 6 miles upstream to do some fly fishing. It took her 20 minutes longer to get there than to return. If the current in the river is 2 miles per hour, then how fast will her boat go in still water.
\n" ); document.write( "---------------------------
\n" ); document.write( "Upstream DATA:
\n" ); document.write( "distance = 6 miles ; rate = b-2 mph; time = 6/(b-2) hrs
\n" ); document.write( "------------------------------------
\n" ); document.write( "Downstream DATA:
\n" ); document.write( "distance = 6 miles; rate = b+2 mph; time = 6/(b+2) mph
\n" ); document.write( "-----------------------
\n" ); document.write( "Equation:
\n" ); document.write( "time up - time down = 1/3 hr
\n" ); document.write( "----
\n" ); document.write( "6/(b-2) - 6/(b+2) = 1/3
\n" ); document.write( "----
\n" ); document.write( "Multiply thru by 3(b^2-9) to get:
\n" ); document.write( "---
\n" ); document.write( "18(b+2)-18(b-2) = b^2-9
\n" ); document.write( "----
\n" ); document.write( "72 = b^2-9
\n" ); document.write( "------
\n" ); document.write( "b^2= 81
\n" ); document.write( "b = 9 mph (speed of the boat in still water)
\n" ); document.write( "=============
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "
\n" );