Answer: The sequence is M(n) = $50 - $3.25*n where n is the number of lunches you bought, and after 12 lunches the amount left in your card is $11
Step-by-step explanation:
You initially had $50 on your card.
After one lunch, you had $46,75
This means that the cost of the lunch was C = $50 - $46.75 = $3.25
After the second lunch, you had $43.50 in your card, this means that the cost this time was c2 = $46.75 - $43.50 = $3.25
Then the arithmetic sequence that represents the amount of money in your card can be written as:
M(n) = $50 - $3.25*n
where n is the number of lunches that you bought.
If you want to calculate the amount of money after 12 lunches, you need to replace n by 12:
M(12) = $50 - $3.25*12 = $11
