Factor completely the expression X5-81x
A x(x4 -81)
B x(x2 +9)(x2-9)
C x(x + 3)'(x-3)
D x(x2 + 9)(x+3)(x - 3)

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?