July	August	September
Sales in Units	500	1000	800
Sales	250,000	500,000	400,000
Less: cost of goods sold	125,000	250,000	200,000
Gross margin	125,000	250,000	200,000
Operating expenses:
Advertising	5,000	5,000	5,000
Salaries & Commissions	72,500	85,000	80,000
Depreciation expense	10,000	10,000	10,000
Utilities expense	12,000	17,000	15,000
Total operating expenses	99,500	117,000	110,000
Net Income	25,500	133,000	90,000

For each of the mixed costs: Salaries & Commissions and Utilities, separate them out into their variable and fixed components using the high-low method. State the cost equation for each mixed cost