In the form of algebra substitution is the method used in simultaneous equations.
E.g y=2x+5 and y=5x-1
Solve for x and y
Since we know two examples of what y is, we can substitute one y in replacement of the other to get.
2x+5=5x-1 then we solve for x to get:
x = 2 sub this back in to get y = 2(2) +5
y = 9
To find out we must divide total cups' amount by a serving's amount, so :

There are 48 servings in the cooler.
Answer:19.2
Step-by-step explanation:
If 1 gallon = 8 pints then you take 8 pints an multiply by 9 your answer is 72
She will need 72 containers