Answer:
see below
Step-by-step explanation:
The expression for the account is
a) 3600 -400M where m is the number of months
b) We want the expression to equal 2000
3600 -400M = 2000
c) 3600 is the initial amount in the account
400 is the amount that the account goes down each month
M is the number of months
2000 is the amount left in the account