In 1978, the amount of earnings required to earn one Social Security credit was $250. Thirty years later, in 2008, this amount was $1,150. What was the percent increase in the amount required to earn a credit, over this 30-year span? Use a percent sign .

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?