Please help me solve it

(NPV and cash flows) A factory is considering the purchase of a new machine for one of its units. The machine costs $100,000. The machine will be depreciated on a straight-line basis over its 10 -year life to a salvage value of zero. The machine is expected to save the company $50,000 annually, but in order to operate it, the factory will have to transfer an employee (with a salary of $40,000 a year) from one of its other units. A new employee (with a salary of $20,000 a year) will be required to replace the transferred employee. What is the NPV of the purchase of the new machine if the relevant discount rate is 8% and the corporate tax rate is 35%