I would say c hope this helps
We have to use the function A(t)= a(1 +/- r)^t
So A is going to be the answer- the area after 8 years. t is going to be 8, because t is time. a is 2400 because that's the starting value. Finally, we're going to turn 5.75% into it's decimal form of .0575. That's going to be r, and because the area is decreasing, we will subtract r from 1.
Our new function is:
A=2400(1-.0575)^8
Simplify a little bit.
A=2400(.9425)^8
Bring .9425 to to power of 8 and then multiply by 2400 because PEDMAS.
A=1494.38366866
The rounded answer is 1494 kilometers squared.
So, the question is 63 is 30% of what number?
That can translate to the equation
63 = 30% · x or 63 = 0.3x
Divide by 0.3 and you get x = 210.
There are 210 students in band.