Answer: c) (-∞, 4) ∪ (5, ∞)
Explanation:
There are two lines:
- The left line is between -∞ and 4 with an open dot at 4.
- The right line is between 5 and +∞ with an open dot at 5.
An open dot is represented with parenthesis ( ).
A closed dot is represented by brackets [ ].
Positive and negative infinity are not actual numbers so they are always represented with parenthesis.
So, the left line is (-∞, 4) and the right line is (5, ∞)