If you could explain this properly I will give u a brainliest! If a, b and c are integers and b^2-4ac is the square root of an integer, explain why the equation has rational roots.

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%