An Account grows at an annual interest rate, it grows by a factor of x=1 + r each year. The function A(x)=800x^4 + 350x^3 + 500x
^2 + 600x gives the amount in the account after 4 years when the growth factor is x. After 5 years, $200 is added to the account. Use the expression for A(x) to write a new expression B(x) that represents how much is in the account after 5 years.
