I need 1-6 please <33

The sum of the reciprocal of a positive number and the reciprocal of 2 more than the number is 3/4 equation: the number is

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%

Find the missing dimension! need asap! tiny square is a =3025 in ²