Answer:
Step-by-step explanation:
I'm assuming you need the age of the bowl. Start with the fact that you have remaining 28% of the original amount before any of it decayed. You always start with 100% of something unless you're told differently. That means that the equation looks like this:
[tex]28=100e^{-.0001t}[/tex] and begin by dividing both sides by 100 to get
[tex].28=e^{-.0001t}[/tex] . To solve for t we have to be able to bring it down from its current position of exponential. To do this we would either take the log or the natural log since the rules for both are the same. However, the natural log is the inverse of e, so they undo each other. We take the natural log of both sides which allows us to pull down the -.0001t. At the same time remember that the natural log and e are inverses of each other so they are both eliminated when we do this.
ln(.28) = -.0001t Now it's easy to solve for t.
[tex]\frac{ln(.28)}{-.0001}=t[/tex] and
[tex]\frac{-1.272965676}{-.0001}=t[/tex] so
t = 12729.65676 years or rounded, 12730 years.
