algebra 2 high school

Question

Samantha opened a savings account with a deposit of $1000. She made yearly deposits of $350 for the next three years. In the 5th year she deposited $500. There were  no additional deposits or withdrawals. The bank account earns an annual interest rate or r. How much money is in Samantha's account after she makes the $500 deposit? Write your answer as a polynomial in terms of x where x=(1+r).

Answer 1

Right after Samantha makes the $500 deposit

The original deposit has been in the account for 4 years.  So the first term of your polynomial is 1000x⁴

Similarly, the next three terms are 350x³, 350x², and 350x

and the last term is 500, since no interest has been earned yet

 

so P(x) = 1000x⁴ + 350x³ + 350x² + 350x + 500