4) Solve the following equations of value. (5 points) a) At an annual discount rate of d, payments of $5500 in one year and $3500 in two years have a present value of $7200. Find d. b) A debt of $8000 is to be repaid with payments of $4050 in 2 years and $X in 3 years. Find X if the loan is charged nominal interest of 5.5% compounded every three-months. c) Petra invests $12,000 at a nominal discount rate of 3.6% compounded 2 times a year. When will her investment be worth $17,000? d) At a nominal rate of interest of i compounded quarterly, a payment of $3500 in 5 years has a present value of $2340. Find