Pr(1/2) for both I believe. If not right sorry.
- We are to find the time (number of minutes) is would take for 23 mg of the substance to be remaining.
- The formula for time is written as:
t = [t1/2 x In(Nt/No)] / In 2
where:
t1/2 = Half life = 4 minutes
No = Initial quantity of the sample = 90 mg
Nt = Amount of the sample left = 23 mg
t = time elapsed = ?
Hence,
t = [4 x In (23/90)] / -In 2
t = 7.8731645610906 minutes
Approximately to the nearest hundredth = 7.87 minutes
Therefore, there will be 23mg of substance remaining after 7.87 minutes.
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Yes....(y-14)(y+14).....................
Answer:
4.5 hours
Step-by-step explanation:
So, let's write a function p(x) which represents the total cost.
Let's let x represent the amount of hours.
The cost of a piece is a constant 10.
And there is a $8 fee per hour. In other words:
We spent a total of $46.
So, substitute in 46 for p(x) and solve for x:
Subtract 10 from both sides:
Divide both sides by 8:
Reduce:
So, we spent about 4.5 hours.