Please show simple steps to calculate the following question

If Gary invested $5,500.00 today in an account that is expected to earn 7.56 percent per year, and he expects to make another investment in the same account in 1 years, then how much money does Gary expect to invest in 1 years if he expects to have $15,700.00 in his account in 7 years?(Round the value to decimal places and enter the positive value)

Ernest invests $3,270.00 in 2 years in an account that is expected to earn 5.87 percent per year, and he expects to invest $3,380.00 in the same account in 3 years, then how much money will Ernest have in his account in 8 years