During july, the following surgical data were recorded
admissions: 1,015
discharges: 997
deaths:
-10 days postop
-10 days postop
deaths:
total
48 hours
48 hours
patients operated on:
surgical procedures:
975
1,018

Consider u = {x|x is a negative real number}which is an empty set? o {x|x eu and x has a negative cube root}o {x|x eu and x has a negative square root}{x|x eu and x is equal to the product of a positive number and -1}{x|x eu and x is equal to the sum of one negative and one positive number?