you plan to purchase a $100,000 house using a 30-year mortgage obtained from you local credit union. the mortgage rate offer to you is 8.25 percent. You will make a down payment of 20 percentof the purchase price. a.calculate your monthly payments on the mortgage b. calculate the amount of interest and separtely principal paid in the 25th payment c. calculate the amount of interest and separately principal paid in the 225th payment d. calculate the amount of interest paid over the life of this mortgage