Could someone please explain these topics? Thank you

Ryan is considering investing in a $400,000 piece of equipment today. It will provide net before- tax operating cash inflows of $120,000 at each years end for 8 years. The company uses straight- line depreciation for a tax purposes. The income tax rate is 40% and the discount rate is 13%. Income taxes are paid at year end. Calculate the net present value of the equipment. Remember income taxes. a. b. c. d. e. f. g. h. Positive $175,852 Positive $89,474 Positive $79,877 Positive $41,486 Positive $126,390 Negative $54,489 Negative $12,941 Negative $64,086 A junk yard needs a smasher. It would add net before-tax cash flows of $80,000 at the end of the first year and $70,000 at the end of the second. The initial cost of the equipment is $100,000 with a salvage value of $0. The required rate of return is 10%. The income tax rate is 40% and paid at year end. In addition, the company uses straight-line depreciation for tax purposes. What is the net present value? a. b. c. d. e. f. g. h. Positive $30,579 Positive $65,290 Positive $13,058 Positive $30,414 Positive $41,322 Negative $8,264 Negative $15,847 Negative $21,653