A mining company is considering purchasing a machine (Machine A) that costs $30,000 and is expected to last 12 years, with a salvage value of $3,000. Annual operating costs are expected to be $9,000 for the first 5 years; of $10,500 annually for the next 4 years, and finally $12,000 in the last 3 years of its useful life. Another alternative for the company is to purchase a highly automated machine (Machine B) at a cost of $58,000. This machine has a useful life of 12 years, given its high technology and specialized design, its operating costs would only be $4,000 per year constantly during the 12 years, while its salvage value at the end of this period is estimated at $12,000. . If the minimum attractive rate of return (MARR) for the company is 20% effective annually:

a) Determine the Net Future Value of each machine and determine the best option, if you perform the analysis before taxes b) Determine the Net Future Value of each machine and determine the best option, if the company's marginal tax rate is 25%, and the assets are depreciated under the guidelines of Mexican legislation with a tax life of 7 years