25 because 4(8)-7 = 32-7 = 25
Ninth term is 2.5
you are adding 0.5 each time
-1,-0.5,0,0.5,1,1.5,2,2.5
Answer:
We can use the sample about 42 days.
Step-by-step explanation:
Decay Equation:



Integrating both sides


When t=0, N=
= initial amount




.......(1)
.........(2)
Logarithm:
130 days is the half-life of the given radioactive element.
For half life,
,
days.
we plug all values in equation (1)






We need to find the time when the sample remains 80% of its original.







We can use the sample about 42 days.
Answer:
1. 112 cm
2 135 ft
3 53.67
Step-by-step explanation: