A group of 70 people attended a ball game. There were four times as many children as adults in the group. Set up a system of equations that represents the number of adults and children who attended the game and solve the system to find the number of adults and the number of children who were in the group.

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?