Each month, a certain manufacturing company’s total expenses

Each month, a certain manufacturing company’s total expenses are equal to a fixed monthly expense plus a variable expense that is directly proportional to the number of units produced by the company during that month. If the company’s total expenses for a month in which it produces 20,000 units are $570,000, and the total expenses for a month in which it produces 25,000 units are $705,000, what is the company’s fixed monthly expense? $27,000, $30,000, $67,500, $109,800, $135,000