document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1129782>Question 1129782</A>: <I><SPAN STYLE=\"word-break: break-all;\"> I've been stuck trying to solve this. Could someone help explain how to correctly set up the equation. Thanks<BR>\n" );
document.write( " A scientist begins with 250 grams of a radioactive substance. After 250 minutes, the sample has decayed to 32 grams. Write an exponential equation <BR>\n" );
document.write( "f(t) representing this situation. (Let f be the amount of radioactive substance in grams and t be the time in minutes.) \r<BR>\n" );
document.write( "\n" );
document.write( "The exponential equation that I thought was correct, but isn't is 250* 2( -t/h). <BR>\n" );
document.write( " </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #746397 by </B><A HREF=/tutors/aboutme.mpl?userid=josmiceli><B>josmiceli(19441)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=josmiceli><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=josmiceli><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=746397\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> Let <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+r+ ALIGN=MIDDLE  ALT=\"+r+\"   DISABLED_style= \"max-width:90%; height:auto;\" > = rate of decay in 250 min<BR>\n" );
document.write( "When <IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+t=250+ ALIGN=MIDDLE  ALT=\"+t=250+\"   DISABLED_style= \"max-width:90%; height:auto;\" > this is true:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+32+=+250%2A%28+1+-+r+%29%5E%28t%2F250%29+ ALIGN=MIDDLE  ALT=\"+32+=+250%2A%28+1+-+r+%29%5E%28t%2F250%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+32+=+250%2A%28+1+-+r+%29%5E%28250%2F250%29+ ALIGN=MIDDLE  ALT=\"+32+=+250%2A%28+1+-+r+%29%5E%28250%2F250%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+32+=+250%2A%28+1+-+r+%29+ ALIGN=MIDDLE  ALT=\"+32+=+250%2A%28+1+-+r+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+1+-+r+=+.128+ ALIGN=MIDDLE  ALT=\"+1+-+r+=+.128+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+r+=+.872+ ALIGN=MIDDLE  ALT=\"+r+=+.872+\"   DISABLED_style= \"max-width:90%; height:auto;\" >, so I can say:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+f%28t%29+=+250%2A%28+1+-+.872+%29%5E%28+t%2F250+%29+ ALIGN=MIDDLE  ALT=\"+f%28t%29+=+250%2A%28+1+-+.872+%29%5E%28+t%2F250+%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "-------------------------------------<BR>\n" );
document.write( "check:<BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+f%28+250+%29+=+250%2A.128%5E%28250%2F250%29+ ALIGN=MIDDLE  ALT=\"+f%28+250+%29+=+250%2A.128%5E%28250%2F250%29+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+f%28250%29+=+250%2A.128%5E1+ ALIGN=MIDDLE  ALT=\"+f%28250%29+=+250%2A.128%5E1+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "<IMG STYLE=\"max-width:80%;\" SRC=/cgi-bin/plot-formula.mpl?expression=+f%28250%29+=+32+ ALIGN=MIDDLE  ALT=\"+f%28250%29+=+32+\"   DISABLED_style= \"max-width:90%; height:auto;\" ><BR>\n" );
document.write( "OK<BR>\n" );
document.write( "Feel free to get another opinion, too\r<BR>\n" );
document.write( "<BR>\n" );
document.write( "\n" );
document.write( " </SPAN>\n" );
document.write( "</TD></TR></TABLE>\n" );