Question 864544
A) If x euros is the discount, then (8-x) is the discount price for admission
B) We know the first 50 will pay 8 euros so the total is 400 euros for the first 50
We also know that 40x is the number of visitors for discount x, therefore our formula should be
y = 400 + 40x(8-x) = 400 + 320x - 40x^2
the given formula is y = 400 +270 -40x^2
let's run an experiment and say x = 3 euros
then 400 + 40*3(5) = 1000 euros which is what we would expect
let's test the formulas
y = 400 +320x - x^2 = 400 + 960 - 360 = 1000
y = 400 + 270 - 360 = 310  which is less than the 400 we know is collected before the discount, therefore the given formula can not be correct