document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=208954>Question 208954</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 3. Translate the problem into a pair of linear equations in two vaiables. Solve the equations using either elimination or substitution. State your answer for the specified variable.\r<BR>\n" );
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document.write( "The speed of a current is 6 mph. If a boat travels 62 miles downstream in the same time that it takes to travel 31 miles upstream, what is the speed of the boat in still water? <BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #157977 by </B><A HREF=/tutors/aboutme.mpl?userid=stanbon><B>stanbon(75887)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=stanbon><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=157977\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Translate the problem into a pair of linear equations in two vaiables. Solve the equations using either elimination or substitution. State your answer for the specified variable. <BR>\n" );
document.write( "The speed of a current is 6 mph. If a boat travels 62 miles downstream in the same time that it takes to travel 31 miles upstream, what is the speed of the boat in still water? <BR>\n" );
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document.write( "Downstream DATA:<BR>\n" );
document.write( "distance = 62 miles ; rate = b+6 ; time = 62/(b+6) hrs<BR>\n" );
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document.write( "Upstream DATA:<BR>\n" );
document.write( "distance = 31 miles ; rate = b-6 ; time = 31/(b-6) hrs<BR>\n" );
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document.write( "Equation: <BR>\n" );
document.write( "time down = time up<BR>\n" );
document.write( "62/(b+6) = 31/(b-6)<BR>\n" );
document.write( "Cross-multiply to get:<BR>\n" );
document.write( "62(b-6) = 31(b+6)<BR>\n" );
document.write( "62b - 6*62 = 31b + 31*6<BR>\n" );
document.write( "31b = (31+62)6<BR>\n" );
document.write( "b = 18 mph (speed of the boat in still water)<BR>\n" );
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document.write( "Cheers,<BR>\n" );
document.write( "Stan H. </SPAN>\n" );
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