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:
the slope is -1
m = -1
Step-by-step explanation:
y2 - y1 y
--------- = ----
x2 - x1 x
= y/x = m
2 - 6
-------
1 - - 3
= -4/4
m = -1
Y÷6=29
y=29 x 6
y=174
Hope I can help u
It's the formula. Base times height.
For example: if 50 is the base and 10 is the height, just multiply them both.
50 x 10 = 500. And I don't think you add area-that's for finding the perimeter
I hope this is what you were looking for! x^2 + xn + xm + mn