Could someone explain how you do your answers? thanks!

For each company, calculate the missing amount. Company Cost of Goods Sold Net Income Sales Revenue | $ 17,800 19,700 12,800 Gross Profit $ 7,900 Lennon Operating Expenses $ 3,450 5,900 $ 4,450 2,900 Harrison McCartney 10,900 8,900 5,900 3,900 1,450 Starr 15,800 9,900 6,450