document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=7628>Question 7628</A>: <I><SPAN STYLE=\"word-break: break-all;\"> The amount of a radioactive tracer remaining after t days is given<BR>\n" );
document.write( "by A = A0 e^–0.18t, where A0 is the starting amount at the beginning of<BR>\n" );
document.write( "the time period. How much should be acquired now to have 40<BR>\n" );
document.write( "grams remaining after 3 days? </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #4239 by </B><A HREF=/tutors/aboutme.mpl?userid=prince_abubu><B>prince_abubu(198)</B></A><img src=\"/images/stars/stars-09.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=prince_abubu><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=4239\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> So the A-final will be 40 grams, right, and you want to know how much you started with 3 days ago? Let's see:\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+40+=+A%5B0%5De%5E%28-0.18%283%29%29+ ALIGN=MIDDLE  ALT=\"+40+=+A%5B0%5De%5E%28-0.18%283%29%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+40+=+A%5B0%5De%5E%28-0.54%29+ ALIGN=MIDDLE  ALT=\"+40+=+A%5B0%5De%5E%28-0.54%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <---- simplified.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+%2840%2Fe%5E%28-0.54%29%29+=+A%5B0%5D+ ALIGN=MIDDLE  ALT=\"+%2840%2Fe%5E%28-0.54%29%29+=+A%5B0%5D+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <---- divide both sides by <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+e%5E%28-0.54%29+ ALIGN=MIDDLE  ALT=\"+e%5E%28-0.54%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" >.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+68.64+=+A%5B0%5D+ ALIGN=MIDDLE  ALT=\"+68.64+=+A%5B0%5D+\"   DISABLED_style= \"max-width:90%; height:auto;\" > <---- Calculate using calculator. You should get approximately 68.64 grams three days ago.\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( "Calculators differ a lot when it comes to how to punch buttons to compute \"e to the something\" power, so I can't really explain this part to you. </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );