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.
1) The ratio of used books to all books is 6:14
2) The ratio of used books to new books is 6:8
Answer:
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Step-by-step explanation:
Answer:
OHHHHHHHH wait It went up by 8%!
Step-by-step explanation:
1) 18h = 252
You divide each side by 18, so you can get "h" alone on a side, and its value on the other side of the equation.
(18h)/18 = 252/18
h = 14 (Answer C)
2) 31d = 186.
Same Thing, you divide each side by 31, so you can get "d" alone on a side, and its value on the other side of the equation.
(31d)/31 = 186/31
d= 6 (Answer B)
3) 55c = 385
Again, same thing, You divide each side by 55, so you can get "c" alone on a side, and its value on the other side of the equation.
(55c)/55 = 385/55
c = 7 (Answer B)
4) 50w = 1050
You divide each side by 50, so you can get "w" alone on a side, and its value on the other side of the equation.
(50w)/50 = 1050/50
w=21 (Answer A)
As you can notice, they all follow the same steps: dividing by the coefficient of the variable both sides, so you can the variable alone on the first side of the equation, and its value on the second side.
Hope this Helps! :)
