Answer:
a = -5
Step-by-step explanation:
15 - a = 20
Move the constant of 15 to the other side by subtracting it.
-a = 5
Divide by -1 to make a positive.
a = -5
Check.
15 - (-5) = 20
15 + 5 = 20
20 = 20
Answer:
x= -6
Step-by-step explanation:
The bones at the time they were discovered when the radioactive element carbon-14 has a half-life of total 5750 years are 10062.5-year-old.
<h3>What is half-lives?</h3>
Half lives is the time interval which is need to decay the atomic nuclei of a radioactive sample.
There is a scientist who determined that the bones from a mastodon had lost 70.3% of their carbon-14. Thus, the fraction remaining is,
f=1-(70.3/100)=1-0.703
f=1-(70.3/100)=0.297
Now the fraction remaining can be given as,
f=(1/2)ⁿ
Here, n is the half life elapsed. Put the value of fraction remaining.
0.297=(1/2)ⁿ
n=1.75
The radioactive element carbon-14 has a half-life of total 5750 years. Thus,
Years=1.75*5750
Years=10062.5
Thus, the bones at the time they were discovered when the radioactive element carbon-14 has a half-life of total 5750 years are 10062.5-year-old.
Learn more about the half lives here;
brainly.com/question/2320811
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Answer:
Step-by-step explanation:
3*√6 + 2√24 + 7√54= P
3√6 + 2√2*2*6 + 7√3*3*6
3√6 + 2*2√6+7*3√6
3√6 + 4√6 + 21√6
28√6 = the perimeter.