Triangle abc has coordinates a(2, -5), b(1, -3), and c(6, 1). if the triangle is rotated 90° counterclockwise about the origin, what are the coordinates of b'?

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?