The answer is 28 years
At = A0 * e^(-k * t)
At = 12 g
A0 = 15 g
k = 7.9 × 10^-3 = 0.0079
t = ?
12 = 15 * e^(-0.0079 * t)
12/15 = e^(-0.0079 * t)
0.8 = e^(-0.0079 * t)
Logarithm both sides (because ln(e) = 1:
ln(0.8) = ln(e^(-0.0079 * t))
ln(0.8) = (-0.0079 * t) * ln(e)
-0.223 = -0.0079 * t
t = -0.223 / -0.0079
t = 28.23
t ≈ 28 years
Answer:

Step-by-step explanation:
Here, we add up two polynomials shown.
The polynomials are:
![[-m^2 + 6]+[-4m^2 +7m + 2]](https://tex.z-dn.net/?f=%5B-m%5E2%20%2B%206%5D%2B%5B-4m%5E2%20%2B7m%20%2B%202%5D)
In order to add up the 2 polynomials shown, we have to see the "like terms" and add them up.
We add up the "
" terms and the constant (number) terms. There is one term with "m", so we leave it like that. Let's add up. Shown below:\
![[-m^2 + 6]+[-4m^2 +7m + 2]\\=-m^2-4m^2+6+2+7m\\=-5m^2+7m+8](https://tex.z-dn.net/?f=%5B-m%5E2%20%2B%206%5D%2B%5B-4m%5E2%20%2B7m%20%2B%202%5D%5C%5C%3D-m%5E2-4m%5E2%2B6%2B2%2B7m%5C%5C%3D-5m%5E2%2B7m%2B8)
This is the sum of the 2 polynomials shown: 
A.Calculate the mean,median and mode.(3 points each) 1.)1,2,3,4,5 2.)2,3,4,5,6,6 3.)6,7,5,4,5,6,2,5
zlopas [31]
Answer:
Step-by-step explanation:
1.)1,2,3,4,5
mean=sum of all values/number of values
=1+2+3+4+5/5
=15/5
mean=3
Mode :
In the given data, no observation occurs more than once.
Hence the mode of the observations does not exist, means mode=0.
Median
1,2,3,4,5
Middle value is 3 so the median is 3.
2.)2,3,4,5,6,6
mean=sum of all values/number of values
=2+3+4+5+6+6/6
=26/6
mean =4.33
Mode
is that value of the observation which occurs maximum number of times so here mode is 6.
Median
2,3,4,5,6,6
4+5/2
9/2
median=4.5
3.)6,7,5,4,5,6,2,5
mean=sum of all values/number of values
=6+7+5+4+5+6+2+5/8
=40/8
mean =5
Mode
is that value of the observation which occurs maximum number of times so here mode is 5
Median
2,4,5,5,5,6,6,7
5+5/2
10/2
median=5