Suppose your business has a special checking account used just for paying the phone bill. The balance is $1040.00 this month. Next month the balance will be $995.80, after that it will be $951.60, and on the third month the balance will be $907.40. Write a rule to represent the balance in the account as an arithmetic sequence. How many months can you pay your phone bill without depositing any more money in the account?

Answer 1

Q1
We can get a table :
Balance 1040 995.8 951.6 907.4
month(m) 0 1 2 3

We get the function:
Tm = 1040-44.2m

Q2
1040 > 44.2m
23.5 > m
It can pay for 23 months without deposting any more money.