At the beginning of year 1, Matilda invests $450 at an annual simple interest rate of 5%. She makes no deposits to or withdrawals from the account.
Which explicit formula can be used to find the account's balance at the
beginning of year 15? What is the balance?
O A. A(n) = 450 + (n)(0.05 · 450); $787.50
OB. A(n) = 450 + (n-1)(0.05); $450.70
O C. A(n) = (450)(n-1)(0.05); $315.00
O D. A(n) = 450 + (n-1)(0.05 · 450); $765.00

i really dont know

step-by-step explanation:

rick has $1400 and sally has $1500

step-by-step explanation:

to find amount of money rick has after 10 years :

principal = $1000 , time = 10 years , rate = 4% annually

to find amount of money sally has after 10 years :

her friend gives to pay her $50 per year, therefore money she has after 10 years = 50 × 10 = $500

also, sally gets $1000 after 10 years,

therefore, total amount of money sally has after 10 years = 500 + 1000 = $1500

so, after 10 years : rick has $1400 and sally has $1500