each year a certain amount of money is deposited in an accound which pays an annual interest rate of r so that at the end of each year the balance in the account is multiplied by a growth factor of x=1+r. 500 is deposited at the start of the first year an additional 200 is deposited at the start of the next year and 600 at the start of the following year write an expression for the value of the account at the end or three years in terms of the growth factor x