11. A shop owner has monthly expenses of $12,000. He receives $3000 a month for allowing people to store there motorhomes on his lot. If the shop owner charger $80 per hour for his services. How many hours does he have to bill in order to make a profit of at least $10,500 per month? 12. An acute angle is represented by 0 = 2x – 20. What are the possible values of x in which the angle will remain acute?