Can somebody please help me on this I don’t understand how to do it well

Barney & noblet customers can choose to purchase a membership for $25 per year members receive 10% off all store purchases 1. how much would a member pay per year if he bought $50 worth of items each year? 2. write a slope-intercept equation that expresses how much a member pays per year using x to represent his purchases per year 3. how much would a member have to spend per year to pay off his membership fee?

Ineed here’s a picture of the question

Show all work to identify the discontinuity and zero of the function f of x equals 6 x over quantity x squared minus 36