I am assuming there are more than one juice box in a package so if the amount of juice boxes in each package is X and there are four packages 4X.
So 4X - 2= Answer
If we make it so that there are 6 juice boxes in each package and use the same method this is what we'll get:
24 - 2= 22
22 would be the juice boxes left over.
I hope this answers your question, if it doesn't use the same method with the number of juice boxes in a package.
Answer:
(5,2) (-2,5) this is how you solve an equation using simple graphd
Let the amount of the first brand be x, and let the amount of the second brand be y.
0.09x + 0.14y = 240 * 0.13 .................(1)
x + y = 240 ..............(2)
y = 240 - x .......................(3)
Plugging the value for y from equation (3) into equation (1), we get:

...............(4)
Equation (4) simplifies to:
-0.05x = -2.4
giving the value for the required amount of 9% vinegar as 48 ml and the required amount of 14% vinegar as 240 - 48 = 192 ml.