Answer:
D. About 800 years
Step-by-step explanation:
Use the half-life equation:
A = A₀ (½)ⁿ
where A is the final amount,
A₀ is the initial amount,
and n is the number of half-lives.
0.90A₀ = A₀ (½)ⁿ
0.90 = (½)ⁿ
To solve for n, take log of both sides:
log 0.9 = n log 0.5
n = (log 0.9) / (log 0.5)
n = 0.152
It takes 0.152 half-lives. The half-life of carbon-14 is 5730 years.
0.152 × 5730 years = 871 years
The closest answer is D.
Because December is really cold
The y-term is -2y. We know this is the y-term because it is a multiple of the variable y and is not multiplied with any other variables.
A coefficient is a number that a variable is multiplied by. When there is a number followed by a variable, the number is the coefficient.
In this case, the coefficient of the y-term is -2. The coefficient is negative because 2y is being subtracted, meaning the 2 is negative rather than positive.
Hope this helps!
