Use the graph to determine the percent of change in CD sales from 2011 to 2012

Solve for x and y: 217x + 131y = 913; 131x + 217y = 827

Which function has the domain x> -11

He weights of 2-pound bags of best dog food are approximately normally distributed with a given mean  and standard deviation  according to the empirical rule, what percentage of the bags will have weights within 3 standard deviations of the mean? 47.5%68%95%99.7%