Show your work! *grade 9 work* please help:)

Write the expression 7x^3-28xy^2 as the product of 3 factors

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%

On ryan's last social studies test there were two types of questions true/false worth 3 points each and multiple choice questions worth 4 points each