I need help. Please answer a, b, c, and d.Thank you!

A man has $340,000 invested in three rental properties. One property earns 7.5% per year on the investment, the second earns 8%, and the third earns 9%. The total annual earnings from the three properties is $28,650, and the amount invested at 9% equals the sum of the first two investments. Let x equal the investment at 7.5%, y equal the investment at 8%, and z represent the investment at 9%. Complete parts (a) through (d) below. a. Write an equation that represents the sum of the three investments. (Type an equation. Do not include the $ symbol in your answer.) b. Write an equation that states that the sum of the returns from all three investments is $28,650. (Type an equation. Do not include the $ symbol in your answer.) c. Write an equation that states that the amount invested at 9% equals the sum of the other two investments. (Type an equation. Do not include the $ symbol in your answer.) d. Solve the system of equations to find how much is invested in each property. A. There is one solution. The man invested $ at 7.5%, $ at 8%, and $ at 9%. B. There are infinitely many solutions. If the man invests $z at 9%, then he invests $ at 7.5% and $ at 8%. (Type expressions using z as the variable.) O C. There is no solution