The answer is 17/22 17/20 because of the fractions
Just do 8 divided by two and then add 25 to that and you get that answer which is $29
This is the derivative of S with respect to r, evaluated at r=8.
dS/dr = 8πr
Substituting r=8 into the above gives the answer of 64π.
The answer is B. 2.5+(-1.5)=1.0
miles