John owns a house painting company. An experienced crew can prep 6 rooms and paint 2 rooms in a week. A novice crew can prep 2 rooms and paint 2 rooms in a week. An experienced crew gets paid $1000 per week and a novice crew gets paid $750 per week. To stay on schedule, John needs at least 12 rooms prepped and 8 rooms painted per day. How many weeks should each crew be scheduled to minimize cost? finding the vertices