document.write( "Question 131830This question is from textbook Introductory Algebra
\n" ); document.write( ": The current in a stream moves at a speed of 3mph. A boat travels 45 miles upstream and 45 miles downstream in a total time of 8 hours. What is the speed of the boat in still water?\r
\n" ); document.write( "\n" ); document.write( "Any help would be greatly appreciated on this! \n" ); document.write( "
Algebra.Com's Answer #96258 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
The current in a stream moves at a speed of 3mph. A boat travels 45 miles upstream and 45 miles downstream in a total time of 8 hours. What is the speed of the boat in still water?
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\n" ); document.write( "Let the speed of the boat in still water be \"b\"
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\n" ); document.write( "Upstream DATA:
\n" ); document.write( "Distance = 45 miles ; Rate = b-3 mph ; Time = d/r = 45/(b-3) hrs.
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\n" ); document.write( "Downstream DATA:
\n" ); document.write( "Distance = 45 miles ; Rate = b+3 mph ; Time = d/r = 45/(b+3) hrs
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\n" ); document.write( "EQUATION:
\n" ); document.write( "time + time = 8 hrs
\n" ); document.write( "45/(b-3) + 45/(b+3 = 8
\n" ); document.write( "45(b+3) + 45(b-3) = 8(b^2-9)
\n" ); document.write( "90b = 8b^2-72
\n" ); document.write( "8b^2-90b-72 = 0
\n" ); document.write( "(b-12)(8b+6)=0
\n" ); document.write( "Positive Solution:
\n" ); document.write( "b=12 mph (boat speed in still water)
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\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.\r
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