Answer:
1 drink costs
and 1 popcorn bag cost

Explanation:
Given:
Sarah spends a total of $47.00 on 12 drinks and 1 bag of popcorn.
Kaylee spends a total of $81.75 on 3 drinks and 9 bags of popcorn
Let the price of 1 drink be x
Let the price of 1 popcorn bag be y
Sarah Spends is given by:

Kayle spends is given by:

Now putting the value of x in sarah spending equation we get

Now Substituting value of y=8 in Sarah spends equation we get

Hence 1 drink costs
and 1 popcorn bag cost
