If x is the no. of days per week you go to school, and f(x) is the total expediture you have per week: we arrive in a equation of: f(x) = 76x. Assuming you go to school 5 days a week, you have: f(x) = 76(5) = 380 pesos. Same with the first function, x is the no. of the days per month thay you go to school, and f(x) is the total expenditure, we still have the equation: f(x) = 76x. Assuming that there are 4 weeks in a month and you go to school 5 days a week: f(x) = 76(4)(5) = 1520 pesos.