a. A new operating system for an existing machine is expected to cost $670,000 and have a useful life of six years. The system yields an incremental after-tax income of $160,000 each year after deducting its straight-line depreciation. The predicted salvage value of the system is $21,400 b. A machine costs $560,000, has a $39,800 salvage value, is expected to last eight years, and will generate an after-tax income of $76,000 per year after straight-line depreciation. Assume the company requires a 12% rate of return on its investments. Compute the net present value of each potential investment. (PV of $1, FV of $1, PVA of $1, and FVA of $1) (Use appropriate factor(s) from the tables provided.)