Answer:
Step-by-step explanation:
(x₁, y₁) = (-2 , -5) & (x₂ , y₂) = (-3 , 1)
Midpoint = 
![=(\frac{-2 + [-3]}{2} ,\frac{-5 + 1}{2})\\\\\\=(\frac{-5}{2} , \frac{-4}{2})\\\\=(-2.5, -2)](https://tex.z-dn.net/?f=%3D%28%5Cfrac%7B-2%20%2B%20%5B-3%5D%7D%7B2%7D%20%2C%5Cfrac%7B-5%20%2B%201%7D%7B2%7D%29%5C%5C%5C%5C%5C%5C%3D%28%5Cfrac%7B-5%7D%7B2%7D%20%2C%20%5Cfrac%7B-4%7D%7B2%7D%29%5C%5C%5C%5C%3D%28-2.5%2C%20-2%29)
Answer:
please can u give full question
Using an exponential function, it is found that it takes 18.6 days for 80% of the material to decay.
The amount of a substance after t days is modeled by:

In which:
- k is the decay rate, as a decimal.
- A(0) is the initial amount.
The half-life is of 8 days, hence
, and this is used to find k.







Hence:

The time it takes for 80% of the material to decay it t for which
, hence:






It takes 18.6 days for 80% of the material to decay.
To learn more about exponential functions, you can take a look at brainly.com/question/24906920
Area= 2πr
So,
If you were to multiply the radius by 2 since 2 is not in the equations,
4*2= 8
8π ft^2 would be the correct answer.
I hope this helps!
~kaikers