Toni and Candace are friends who work at the same store. Toni's total weekly salary, in dollars, if she sells x items is given by S(x) =4+7x, and Candace's total weekly salary, in dollars, if she sells x items is given by S(x) =2+8x
Assuming that they sell the same number of items in a week, what is the minimum number of items they have to sell so that Candace's weekly salary is at least $100 more than Toni's?
Create a new function, D(x), to solve this problem.