Can you me find the area of a polygon

What is the product of the radical expression. (7-2square root) (8+2 square root)

Which of the following is the true for f(x) = 5cos

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%