40
8x5=40
10x4=40
Hope this helps
Answer:
hiii...hopefully this is correct x=12
Answer:
A
Step-by-step explanation:
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
Answer:
2/3, 5/6, 2/9, 11/18
Step-by-step explanation: