In this item, it is assumed that we are to determine the speed at which the car will have the best gas mileage. This can be done by deriving the equation and equating it to zero.
M(s) = -1/28s² + 3s - 31
Deriving,
dM(s) = (-1/28)(2s) + 3 = 0
s = 42
Hence, the speed at which the best mileage is achieved is mi/h.
Then your amount was reduced to $15 less
Answer:
Step-by-step explanation:
All those words! Just use math.

If you divide the amount of Dollars by the amount of Euros you get the price of 1 Euro in Dollars.
$600/450€ = $1,33 per each Euro