Answer:
The correct option 4.
Explanation:
The given equation is
.... (1)
Let x is the number of pretzels sold and y is the number of popcorn bags sold.
Total sales is defined as
... (2)
From (1) and (2) it is clear that,
The cost of each pretzel is $2.75 or 275 cents. The cost of each popcorn bag is $3.25 or 325 cents ($1 = 100 cents). Total sales is $215.

Pretzels cost is 50 cents less than popcorn bags. The variable x represents the number of pretzels sold and y represents the number of popcorn bags sold. The total sales was $215.
Therefore the correct option 4.