Answer:
The answer to your question is: (∞ , 3]
Explanation:
Remember that to express an inequality, are used ( ) and [ ].
( ) are used when the point is not consider in the interval.
[ ] are used when the point is consider or is part of the interval.
Also, an empty point indicates that the number is not consider in the interval.
and, a filled point indicates that the number is consider in the interval.
For your question, the interval will be:
(∞ , 3]