document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=389014>Question 389014</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Sam wants to swim in a river with a current of 2 miles an hour. He can travel 8 miles upstream and back in 3 hours. How fast is he in still water? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #275483 by </B><A HREF=/tutors/aboutme.mpl?userid=lwsshak3><B>lwsshak3(11628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=lwsshak3><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=275483\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> let x =swim speed of of sam in still water<BR>\n" );
document.write( "time = distance÷speed<BR>\n" );
document.write( "downstream speed of sam =stillwater + current speed=(x+2)<BR>\n" );
document.write( "upstream speed of sam= stillwater -current speed=(x-2)\r<BR>\n" );
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document.write( "time downstream + time upstream = 3\r<BR>\n" );
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document.write( "8/(x+2) +8/(x-2) = 3<BR>\n" );
document.write( "LCD: (x=2)(x-2)<BR>\n" );
document.write( "8(x-2)+8(x+2) =3(x+2)(x-2)=3(x^2-4)<BR>\n" );
document.write( "8x-16+8x+16=3x^2-12<BR>\n" );
document.write( "3x^2-16x-12 =0<BR>\n" );
document.write( "(3x+2)(x-6) =0<BR>\n" );
document.write( "x=6 or x=-2/3 (rejected, speed cannot be negative)<BR>\n" );
document.write( "ans: swim speed of sam in still water = 6 mi/hr </SPAN>\n" );
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