Joel and sharply are selling flowers bulbs for a school fundraiser. Customers can buy bags of wildflowers bulbs and bags of daffodils bulbs. Joel sold 12 bags of wildflowers bulbs and 1 bag of daffodil bulbs for a total of 81. Sharply sold 4 bags of wildflowers bulbs and 2 bags of daffodil bulbs for a total of $42. What is the cost of one bag of wildflowers bulbs