Answer:
The function that represents the mass of the sample after t days is
.
The percentage rate of change per hour is of -2.46%.
Step-by-step explanation:
Exponential amount of decay:
The exponential amount of decay for an amount of a substance after t days is given by:

In which A(0) is the initial amount, and r is the decay rate, as a decimal.
Element X is a radioactive isotope such that its mass decreases by 59% every day. The experiments starts out with 390 grams of Element X.
This means, respectively, that 
So



The function that represents the mass of the sample after t days is
.
Hourly rate of change:
Decreases by 59% every day, which means that for 24 hours, the rate of change is of -59%. So
-59%/24 = -2.46%
The percentage rate of change per hour is of -2.46%.
3x-5=19-x
3x-5-19+x=0
4x-24=0
4x=24
x=6
N - 2 = 10n + 4/2
-2 = 9n + 4/2
-4/4 = 9n
-1 = 9n
-9 = n
N is -9.
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Answer:
Part A: The total is 57.58
Part B: 19.19 each
Step-by-step explanation:
Part A: 15(3) +3.50(3)=55.50
55.50 plus the 3.75% tip (not really addition i dont know how to find a percentage so i looked that part up) but it come out to $57.58
Part B: 57.58 divided by 3 is $19.19 ( I do 3 because Maria and 2 more friends)
Hope it helps and that it is 100% correct dont come at me if something is wrong with my math
3.95 × 3.81 = 15.0485
The road was 15.0485 miles long after the renovation.
Hope this helps!