document.write( "Question 1128806: If 10 g of a radioactive substance are present initially and 9 yr later only 5 g remain, how much of the substance will be present after 14 yr?\r
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Algebra.Com's Answer #745315 by josgarithmetic(39625) $\"\"$ $\"About$

You can put this solution on YOUR website!
After 14 years, from what?\r
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\n" ); document.write( "\n" ); document.write( " $\"y=10%2Ab%5Ex\"$ \r
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\n" ); document.write( "\n" ); document.write( " $\"10%2Ab%5E9=5\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"b%5E9=1%2F2\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"log%28%28b%5E9%29%29=log%28%281%2F2%29%29\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"9%2Alog%28%28b%29%29=log%28%281%2F2%29%29\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"log%28%28b%29%29=%281%2F9%29%2Alog%28%281%2F2%29%29\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"log%28%28b%29%29=log%28%28%280.5%29%5E%281%2F9%29%29%29\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"b=%280.5%29%5E%281%2F9%29\"$ \r
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\n" ); document.write( "\n" ); document.write( " $\"b=0.9259\"$ \r
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\n" ); document.write( "\n" ); document.write( " $\"highlight%28y=10%2A%280.9259%29%5Ex%29\"$ --------the model to use.\r
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\n" ); document.write( "this is not the only exponential model possible.
\n" ); document.write( "notice that the given data is for half-life. \n" ); document.write( "

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