The answers are presented but I don't understand how to get there. Please explain using words each step

Cannula Vending Corporation is expanding operations and needs to purchase additional vending machines. There are currently two companies, Viscera, Inc. and Gullet International, that produce and sell machines that will do the job. Information related to the specifications of each company's machine are as follows (Ignore income taxes.): Cannula's discount rate is 18%. Cannula uses the straight-line method of depreciation. Using net present value analysis, which company's machine should Cannula purchase and what is the approximate difference between the net present values of the competing company's machines? Which company's machine should Cannula purchase based on NPV analysis? Note that both machines have negative net present values. Select the machine that costs the least in today's dollars. What is the difference between the machine's NPVs