document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=276156>Question 276156</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I need help solving this! How long will it take a sample radioactive substance to decay to half of its original amount, if it decays according to the function A(t)=450e^-0.157t, where t is the time years? Round to the nearest hundreth year. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #201363 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=201363\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 1/2 = 450 e^(-0.157t)\r<BR>\n" );
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document.write( ".5 / 450 = e^(-0.157t)\r<BR>\n" );
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document.write( "ln(.5 / 450) = -0.157 t\r<BR>\n" );
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document.write( "[ln(.5 / 450)] / (-0.157) = t </SPAN>\n" );
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