Every 3 weeks=21 days. this is because 21 is the lowest common factor of 7 and 3
I don’t know if this will help....
Answer:
The bones were 12,485 years old at the time they were discovered.
Step-by-step explanation:
Amount of the element:
The amount of the element after t years is given by the following equation, considering the decay rate proportional to the amount present:

In which A(0) is the initial amount and k is the decay rate, as a decimal.
The radioactive element carbon-14 has a half-life of 5750 years.
This means that
, and we use this to find k. So







So

A scientist determined that the bones from a mastodon had lost 77.8 % of their carbon-14. How old were the bones at the time they were discovered?
Had 100 - 77.8 = 22.2% remaining, so this is t for which:

Then






The bones were 12,485 years old at the time they were discovered.
Answer:
domain:

range:
![( - \infty ,4]](https://tex.z-dn.net/?f=%28%20-%20%20%5Cinfty%20%2C4%5D)
equation:

Step-by-step explanation:
domain is all X values and the X values will extent till infinity in both negative and positive direction, the range is all y values and the y value will go from negative infinity all the way to 4, where the graph stops.
Answer:
30 X 40 is 1,200
Step-by-step explanation:
I used a calculator lol