Question 1143472
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In 700 days the radioactivity of a sample decreases by 29 percent. 
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??


{{{y=pe^(-kx)}}}
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{{{ln(y)=ln(p)-kx}}}
{{{ln(y)-ln(p)=-kx}}}
{{{kx=ln(p)-ln(y)}}}
{{{k=(ln(p)-ln(y))/x}}}

{{{k=(ln(p/y))/x}}}
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{{{k=ln(100/71)/700}}}

{{{k=0.0004893}}}

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{{{highlight_green(y=pe^(-0.0004893x))}}}




HALF-LIFE

{{{x[half]=ln(2)/k}}}

{{{x[half]=ln(2)/0.0004893}}}

1416