document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=220956>Question 220956</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The speed of a boat in still water is 10mph.  It travels 15 miles upstream and 15 downstream in a total of 4 hours. what is the speed of the current? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #165826 by </B><A HREF=/tutors/aboutme.mpl?userid=checkley77><B>checkley77(12844)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=checkley77><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=165826\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> D=RT <BR>\n" );
document.write( "(15+15)=[(10-X)*(10+X)]4<BR>\n" );
document.write( "30=[100-X^2]4<BR>\n" );
document.write( "30=400-4X^2<BR>\n" );
document.write( "4X^2=400-30<BR>\n" );
document.write( "4X^2=370<BR>\n" );
document.write( "X^2=370/4<BR>\n" );
document.write( "X^2=92.5<BR>\n" );
document.write( "X=SQRT92.5<BR>\n" );
document.write( "X=9.617 MPH FOR THE CURRENT.<BR>\n" );
document.write( "PROOF:<BR>\n" );
document.write( "(15+15)=[(10-9.617)+(10+9.617)]4<BR>\n" );
document.write( "30=[.383*19.617)4<BR>\n" );
document.write( "30=7.51.4*4<BR>\n" );
document.write( "30=30<BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );