For this case we propose a system of equations:
x: Represents the amount of small popcorn tubs
y: Represents the amount of large popcorn tubs
According to the data we have to:
(Spending all the money in your wallet)
(Buying 7 popcorn tubs)
From the second equation we have:

Substituting in the first equation:

Thus, Katie can buy 3 large tubs of popcorn.
So:

In addition, you can buy 4 small tubs of popcorn.
Answer:
3 large popcorn tubs.
4 small popcorn tubs.
You should try and put it in another way it doesn’t make sense
Answer:
The option in the top right...
Step-by-step explanation:
D = (5-1)/(13-(-3)) = 0.25
f(13) = 13d + x = 13 * 0.25 + a = 3.25 + a = 5
a = 1.75
f(x) = 1.75 + 0.25x
64 divided by 4 is 16. The answer is 16 I believe!
Edit: I realized you were asking for the cost. That would be 48. 64 - 16 = 48.