To enroll in lessons to learn about pottery wheel throwing, you must pay an rollment of $20 for each lesson. The pottery studio also charges you $2.99 pe pound for the amount of clay used.To enroll in lessons to learn about pottery wheel throwing, you must pay an enrollment of $20 for each lesson. The pottery studio also charges you $2.99 per pound for the amount of clay used. Write an expression for the total cost of a person using c pounds of clay during a lesson. Use the expression to calculate the cost of a lesson where Sam uses 3.5 pounds of clay.