Barrett's mail manufacturing is a company that produces chain mail. their most popular product is saw cut metal links that hobbyists can use to make their own creations . the company recently spent 789 on advertising, which they can hope to make back quickly .the wire used to produces one ounce of links costs 1 ,but the finished links sell for 4 per ounce . eventually the company will make back its investment and break even. what will their expenses and sales both equal ? how many links must be sold?