document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=47511>Question 47511</A>: <I><SPAN STYLE=\"word-break: break-all;\"> A skin heals according to N(t)+N(o)e^-0.02t, where N is the number of square centimeters of unhealed skin t days after an injury, and N(o) is the number of square centimeter covered by the original wound.  How many days (to the nearest tenth ofa day) will it take for 50% of the wound to heal? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #31360 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=31360\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> N(t)=N(o)e^-0.02t  How many days (to the nearest tenth ofa day) will it take for 50% of the wound to heal?\r<BR>\n" );
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document.write( "50% of N(o) = 0.5N(o)\r<BR>\n" );
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document.write( "0.5N(o) = N(o)e^(-0.02t)<BR>\n" );
document.write( "0.5 = e^(-0.2t)<BR>\n" );
document.write( "Take the natural log to get:<BR>\n" );
document.write( "-0.2t=ln(0.5)<BR>\n" );
document.write( "-0.2t=-0.6931...<BR>\n" );
document.write( "t=3.5 days<BR>\n" );
document.write( "Cheers,<BR>\n" );
document.write( "Stan H.\r<BR>\n" );
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document.write( " </SPAN>\n" );
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