document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=975956>Question 975956</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the half-life to the nearest tenth of a year of a radioactive substance that decays from 65 mg to 17.55 mg in 20years according to the exponential decay model y = ae^&#8722;bx where a is the initial amount and y is the amount remaining after x years. </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #597698 by </B><A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><B>josgarithmetic(39628)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josgarithmetic><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=597698\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=y=a%2Ae%5E%28-bx%29 ALIGN=MIDDLE  ALT=\"y=a%2Ae%5E%28-bx%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=ln%28y%29=ln%28a%29-bx ALIGN=MIDDLE  ALT=\"ln%28y%29=ln%28a%29-bx\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=ln%28y%29-ln%28a%29=-bx ALIGN=MIDDLE  ALT=\"ln%28y%29-ln%28a%29=-bx\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=ln%28a%2Fy%29=bx ALIGN=MIDDLE  ALT=\"ln%28a%2Fy%29=bx\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=b=%281%2Fx%29ln%28a%2Fy%29 ALIGN=MIDDLE  ALT=\"b=%281%2Fx%29ln%28a%2Fy%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "VALUE OF b:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=%281%2F20%29ln%2865%2F17.55%29 ALIGN=MIDDLE  ALT=\"%281%2F20%29ln%2865%2F17.55%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28b=0.06547%29 ALIGN=MIDDLE  ALT=\"highlight%28b=0.06547%29\"   DISABLED_style= \"max-width:90%; height:auto;\" >\r<BR>\n" );
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document.write( "FIND HALF-LIFE:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=ln%28a%2Fy%29=bx ALIGN=MIDDLE  ALT=\"ln%28a%2Fy%29=bx\"   DISABLED_style= \"max-width:90%; height:auto;\" >, from earlier step,<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=%281%2Fb%29ln%28a%2Fy%29 ALIGN=MIDDLE  ALT=\"x=%281%2Fb%29ln%28a%2Fy%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=x=%281%2F0.06547%29ln%281%2F%281%2F2%29%29 ALIGN=MIDDLE  ALT=\"x=%281%2F0.06547%29ln%281%2F%281%2F2%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=highlight%28x=%281%2F0.06547%29ln%282%29%29 ALIGN=MIDDLE  ALT=\"highlight%28x=%281%2F0.06547%29ln%282%29%29\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-----That will be the half-life.  You can finish computing it. </SPAN>\n" );
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