document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=264590>Question 264590</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A boat can go 45 mph in still water. It takes as long to go 630 miles upstream as it does to go downstream 720 miles. How fast is 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 #194785 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=194785\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> D=RT<BR>\n" );
document.write( "630=(45-C)T<BR>\n" );
document.write( "T=630/(45-C)<BR>\n" );
document.write( "720=(45+C)T<BR>\n" );
document.write( "T=720/(45+C) BECAUSE THE 2 TIMES ARE THE SAME SET THE 2 EQUATIONS EQUAL & SOLVE FOR C (THE CURRENT).<BR>\n" );
document.write( "630/(45-C)=720/(45+C) CROSS MULTIPLY.<BR>\n" );
document.write( "720(45-C)=630(45+C)<BR>\n" );
document.write( "32,400-720C=28,350+630C<BR>\n" );
document.write( "-720C-630C=28,350-32,400<BR>\n" );
document.write( "-1,350C=-4,050<BR>\n" );
document.write( "C=-4,050/-1,350<BR>\n" );
document.write( "C=3 MPH. IS THE SPEED OF THE CURRENT.<BR>\n" );
document.write( "PROOF:<BR>\n" );
document.write( "630/(45-3)=720/(45+3)<BR>\n" );
document.write( "630/42=720/48<BR>\n" );
document.write( "15=15\r<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );