document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=960242>Question 960242</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 100e^-0.13t=50\r<BR>\n" );
document.write( "\n" );
document.write( "100=20(1.2)^x+2 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #586831 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=586831\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> a.) 100e^-0.13t=50 <BR>\n" );
document.write( "e^(-0.13t)=50/100=1/2<BR>\n" );
document.write( "take log of both sides<BR>\n" );
document.write( "-0.13t*lne=ln(1/2)<BR>\n" );
document.write( "lne=1<BR>\n" );
document.write( "-0.13t=ln(1/2)<BR>\n" );
document.write( "t= ln(1/2)/-0.13<BR>\n" );
document.write( "t=-5.3319<BR>\n" );
document.write( "..<BR>\n" );
document.write( "b.) 100=20(1.2)^x+2<BR>\n" );
document.write( "98=20(1.2)^x<BR>\n" );
document.write( "1.2^x=98/20=4.9<BR>\n" );
document.write( "xlog1.2=log4.9<BR>\n" );
document.write( "x=log 4.9/log1.2<BR>\n" );
document.write( "x=8.7167 </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );