What is the equivalent uniform annual cost of two hydraulic systems with expected 30-year life with the following features? The first hydraulic system requires annual operating, maintenance and repair cost of $1000, and it has a useful life of 15 years. Its initial cost is $35,000, and it has a salvage value of $6000 at the end of its useful life. The second hydraulic system has an initial cost of $18,000, and is expected to be unserviceable after ten years. It requires $500 annual operating, maintenance, and repair cost and has a zero salvage value after its 10-year useful life. Assume the interest rate is 7%.