The answer to this is letter D
Answer:
-5
Step-by-step explanation:
multiple the second equation by negative then subtract or add the equations and the answer will be negative 5
The amount of substance left of a radioactive element of half life,

after a time, t, is given by:

Given that <span>potassium-40 has a half life of approximately 1.25 billion
years.
The number of years it will take for 0.1% of potassium-40 to remain is obtained as follows:

Therefore, </span><span>the maximum age of a fossil that we could date using 40k is
12.5 billion years.</span>
8:9 because you tak the square root of both
Answer:
2.01
Step-by-step explanation: