please ahowbthe formulas used for a,b, c,d please

any quarterly 9.4 Find the following values assuming a regular, or ordinary, annuity: a. The present value of $400 per year for ten years at 10 percent b. The future value of $400 per year for ten years at 10 percent c. The present value of $200 per year for five years at 5 percent d. The future value of $200 per year for five years at 5 percent 9.5 Repeat Prob