PLEASE SOLVE IT BY EQUATIONS NOT EXCEL AND OTHER TECHNOLOGY, HELP ME TO COMPUTE THESE TWO PROBLEMS BY HAND. THANKS

1. A borrows $20,000 from B and agrees to repay it with 20 equal annual installments of principal in addition to the interest on the unpaid balance at 3% effective. After 10 years B sells the right to future payments to C, at a price which yields C 5% effective over the next 5 years and 4% effective over the final 5 years. Find the price which C should pay to the nearest dollar. ANSWER:9191

2. A loan is being repaid by 15 annual payments at the end of each year. The first 5 installments are 4,000 each, the next 5 are 3,000 each, and the final 5 are 2,000 each. Find expressions for the outstanding loan balance immediately after the second 3,000 installment. (a) prospectively; (b) retrospectively. ANSWER:(a) 3000a3 + 2000v 3a5 (b) L(1 + i) 7 4000s5 (1 + i) 2 3000s2 , where L is the original amount