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.
Answer:
125 min
Step-by-step explanation:
given :
4 words -----> takes 1 min
1 word --------> takes 1/4 min
500 words ------> takes (1/4) x 500 = 125 min
Answer:Selling price is 425
Step-by-step explanation:
Answer:
umm...
Step-by-step explanation:
The value of f(r - 2) is 6r - 5
<h3>What is a function?</h3>
Function can be defined as an expression, rule, or law that defines a relationship between one variable known as the independent variable and another called the dependent variable.
From the information given ,we have;
f(x)= 6x+7, with f ( r - 2)
From here, we have that x = r -2
Now, let's substitute x as r - 2 in the function given;
f(x) = 6x + 7
f(r - 2) = 6 ( r - 2) + 7
Expand the bracket
f(r - 2) = 6r - 12 + 7
collect like terms
f(r - 2) = 6r - 5
Thus, the value of f(r - 2) is 6r - 5
Learn more about functions here:
brainly.com/question/6561461
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