Please solve hand solution (not excel).

thank you:)

In the use of unmanned aerial vehicles (UAVs) that will shape the future of UAV applications an online shopping company has purchased a group of UAVs for $74000. The market value is expected to decrease by $4000 per year. Also, the UAVs will be depreciated within a 9 years. As cargo drones are a proven technology for the logistics industry, it is expected that the purchase of the group of UAVs will increase the company's revenue by $12000 annually. Although, there is an expectation about the related operating expenses to be $2000 annually to operate fee-charging UAV services at certain times, the online shopping company's effective income tax rate of is 40%, and its after-tax MARR is 15% per year. The company decides to use the cargo drones for 9 years to simplify the transportation of goods while offering faster. more environmentally friendly service than the alternative. a) What would be the equivalent after-tax annual worth of this investment? b) Is this investment profitable? Write your comments about your results