Please help me, its just question 11-14 !!

The step function g(x) is defined as shown. what is the range of g(x)? ***answer choices in picture.

Which expression is equivalent to sq-80

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?