The weekly expenses (in RM) of Jack and Melissa are summarized in the table below, given that x is number of working days in a week, and they work for same number of days in a particular week.
(a) Write the sum of the weekly expenses of Jack and Melissa. [3]
(b) Write the sum of the weekly expenses of Jack and Melissa.

(c) Write a quadratic equation in the form ax² + bx + c = 0, given the expenses spent on food by Jack and Melissa are the same in a particular week. Hence, state the number of days they work in that particular week. [3]​