Match up the word with the definition

Identify a1 and r for the geometric sequence an= -256(-1/4) n-1

What is the result of adding the system of equations? 2x+y=4 3x-y=6

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%