Question

determine if the set is the empty set. {x | x < 9 and x > 12} choose the correct answer below. the set is the empty set. the set is not the empty set.

Explanation:

Step1: Analyze the set conditions

The set is defined as $\{x \mid x < 9 \text{ and } x > 12\}$, meaning we need a number that is simultaneously less than 9 and greater than 12.

Step2: Evaluate logical consistency

There is no real number (or any number) that can satisfy both $x < 9$ and $x > 12$ at the same time, since 9 is less than 12.

Answer:

The set is the empty set.