document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=138079>Question 138079</A>This question is from textbook <A HREF=http://www.amazon.com/exec/obidos/ASIN/0130442631/algebrahomeworkh>Prentice Hall Algebra 1</A><BR>\n" );
document.write( ": <I><SPAN STYLE=\"word-break: break-all;\"> I would very much appreciate if you could answer this question I do not know what category this is:\r<BR>\n" );
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document.write( "The speed of a boat in still water is 10km/h. The boat travels 12km upstream and 28km downstream in a total time of 4 hours. What is the speed of the stream?\r<BR>\n" );
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document.write( "Thank You </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #100861 by </B><A HREF=/tutors/aboutme.mpl?userid=scott8148><B>scott8148(6628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=scott8148><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/cgi-bin/show-face.mpl?user=scott8148><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=100861\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> let x=current __ rate upstream is 10-x and rate downstream is 10+x\r<BR>\n" );
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document.write( "d=rt, so t=d/r __ time up plus time down is 4 hr\r<BR>\n" );
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document.write( "4=[12/(10-x)]+[28/(10+x)] __ multiplying by (10-x)(10+x) __ 4(10-x)(10+x)=12(10+x)+28(10-x)\r<BR>\n" );
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document.write( "400-4x^2=400-16x __ adding 4x^2-400 __ 0=4x^2-16x __ dividing by 4 __ 0=x^2-4x\r<BR>\n" );
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document.write( "factoring __ 0=x(x-4) __ x=0 and x=4 (zero is not realistic) </SPAN>\n" );
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