Can someone help me find my error A rectangle has perimeter of 102 cm. The width of the rectangle is 5 cm shorter than the length. Find the length and width of rectangle. Only an algebraic solution will be accepted

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%