6. The start up are running business and want to minimize equipment expenses. For a particular piece of equipment, the costs can be broken into initial outlays to buy the equipment, fixed annual expenses to keep the equipment in the inventory, and repair costs which we anticipate rising as the equipment gets older. A widget press costs 10,000B to buy, and the operating expenses are 500B per year, and the total repair costs are 300t2 over the first t years. What is the optimal length of time to use a widget press before replacing it? You should shown your answer algebraically and graphically