Answer:
The hourly decay rate is of 1.25%, so the hourly rate of change is of -1.25%.
The function to represent the mass of the sample after t days is 
Step-by-step explanation:
Exponential equation of decay:
The exponential equation for the amount of a substance is given by:

In which A(0) is the initial amount and r is the decay rate, as a decimal.
Hourly rate of change:
Decreases 26% by day. A day has 24 hours. This means that
; We use this to find r.



![\sqrt[24]{(1-r)^{24}} = \sqrt[24]{0.74}](https://tex.z-dn.net/?f=%5Csqrt%5B24%5D%7B%281-r%29%5E%7B24%7D%7D%20%3D%20%5Csqrt%5B24%5D%7B0.74%7D)



The hourly decay rate is of 1.25%, so the hourly rate of change is of -1.25%.
Starts out with 810 grams of Element X
This means that 
Element X is a radioactive isotope such that its mass decreases by 26% every day.
This means that we use, for this equation, r = 0.26.
The equation is:



The function to represent the mass of the sample after t days is 
Answer: 
Step-by-step explanation:
As per given,
Number of wives = 
Number of sacks = 
Number of cats = 

Number of kits = 
Now , the total number of kits, cats, sacks, and wives going to St. Ives = 
Hence, the required ex[pression: 
The answer to this equation is 1412 or 21-15
Teachers often all this problem a donut problem because it’s like the donut hole getting cut out of the middle. The way that you solve this is to find the area of the whole yard and subtract the area of the fountain. Since they are rectangles we’re going to use A = LW
Area of yard - Area of fountain
A = (8x)(9x) - (2x)(5x)
A = 72 x^2. - 10 x^2
A 62 x^2