Once they're empty, I guess.
Did you put it the wrong way around?
Because it would be after four hours in this case.
Is -x^(2)-x+20 an answer choice?
if so its right
If 4 lemonades are $7.25 divide that by 2 and it's $3.62 subtract that from 23.50 and its $19.87, divided by two the answer is $6.62.
(y-y1)=m(x-x1)
y-6=3(x-0)
y-6=3x-0
Add 6 to both sides
y=3x+6
This is the equation of the line