About 92 days are taken for 90 % of the material to <em>decay</em>.
The mass of radioisotopes (
), measured in milligrams, decreases exponentially in time (
), measured in days. The model that represents such decrease is described below:
(1)
Where:
- Initial mass, in milligrams.
- Current mass, in milligrams.
- Time constant, in days.
In addition, the time constant is defined in terms of half-life (
), in days:
(2)
If we know that 
, 
and 
, then the time required for decaying is:
About 92 days are taken for 90 % of the material to <em>decay</em>.
We kindly invite to check this question on half-life: brainly.com/question/24710827
1st way- 3^2 * 3^3
2nd way- 3 * 3^4
3rd way- 3^0 * 3^5
Bob has a garden
the area is 75 square feet
the legnth is 3 times the width
solve
75=lw
l=3w
subsitute
75=3w times w=3w^2
75=3w^2
sdivide by 3
25=w^2
square root
5=width
subsitute
3w=l
3 times 5=l
l=15
width=5
legnth=15
Answer:
swipe on solution for full explanation
