Please show me how to do both problems

(1 point) Juan purchases an annuity for $4870 that will make 20 annual payments, the first to come in one year. If the effective rate of interest is 7.9%, how much is each annual payment? Payment =$ (1 point) Sally has a sum of $20000 that she invests at 10% compounded monthly. What equal monthly payments can she receive over a period of a) 10 years? Payment =$ b) 16 years? Payment =$ Note: You can earn partial credit on this