Your beginning balance on your lunch account is $42. You buy lunch for $1.80 every day and sometimes buy a snack for $0.85. After 20 days, you have a balance of $0.05. How many snacks did you buy?

The answer to your question is: I bought 7 snacks

Step-by-step explanation:

Data

beginning balance = $42 = b

lunch = $1.80 = l

snack = $ 0.85 = s

final balance = $0.05 = f

f = b - 1.8l - 0.05s

0.05 = 42 - 1.8l - 0.85s

After 20 days I spent = 1.8 (20) in lunches = $36

0.05 = 42 - 36 - 0.85s

0.05 = 6 - 0.85s

0.05 - 6 = - 0.85s

-5.95 = - 0.85s

s = - 5.95/-0.85

s = 7