Answer:
c. the empty set
Step-by-step explanation:
set of {x | x < - 5} n {x | x > 5}
The set x < - 5 comprises of real numbers that are less than -5;
(-6, -7, -8, -9, -10, -11, ......)
On the other hand, the set x > 5 comprises of real numbers greater than 5;
(6, 7, 8, 9, 10, 11, ......)
Clearly, the intersection of the above sets is empty, in that the intersection has no elements.
Therefore, {x | x < - 5} n {x | x > 5} is an empty or null set