Avery is in the business of manufacturing phones. She must pay a daily fixed cost to rent the building and equipment, and also pays a cost per phone produced for

materials and labor. The labor and materials cost $100 for each phone manufactured,

and the total cost of producing 3 phones in a day would be $600. Write an equation

for C, in terms of p, representing total cost, in dollars, of producing p phones in a

given day.