Answer:
A bag of pop corn costs $8, and each Pretzel costs $4.25.
Explanation:
Let
be the price of popcorn, and
the price of Pretzels. If the girl bought 2 bags of popcorn and 5 Pretzels and it cost her $37.25, we have the equation
(this says that the cost of 2 popcorn bags plus 5 pretzels equals $37.25) .
And, since Zoe bought 8 popcorn bags and 9 Pretzels with a total price of $102.25, we get the equation
(this says that the cost of 8 popcorn bags plus 9 Pretzels equals $102.25).
Thus, we have two equations
1.
2.
and we solve them by first multiplying equation (1) by 4:
,
and then subtracting it from equation (2):
Now we put this value of
into equation (1) and get:
and we solve for
to get:
Therefore, a bag of popcorn costs $8, and each Pretzel costs $4.25.