A school cafeteria charges $1.50 for breakfast and $3.00 for lunch. At the beginning of the school year, a student adds exactly enough money to their meal account to pay for both breakfast and lunch for ten days. (a) Write an equation in standard form that models the possible combinations of breakfasts and lunches the student can afford to buy.
(b) Graph the equation. (c) The student eats breakfast for four days and then decides to start eating breakfast before coming to school in the morning. How many total lunches can the student buy before having to add more money to their meal account?