Answer
Fill the blanks with:
2, 5, 2, 5
Work Step by Step
An interval may be annotated as
$[a,b],\ (a,b],\ [a,b),\ (a,b),\ (-\infty,b],\ (-\infty,b),\ [a, \infty),\ (a, \infty).$
It contains numbers between the left and right borders.
The inequality signs depend on whether a border is included in the set or not.
The bracket "[", or "]" means "border included" and the sign is "$\leq $" .
The parenthesis "(" or ")" means "border excluded" and the sign is "$\lt $".
$\pm\infty $ is an annotation for "no border", so it is always accompanied by a parenthesis
For example
$[a,b) = \{x\ |\; a\leq x \lt b\ \ \}\\
(-6,\infty) = \{x\ |\; x \gt -6\ \ \}\\
(-\infty,3] = \{x\ |\; x \leq 3\ \ \}$
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"[2..." means that the left border 2 is included, "... 5)" means that the right border 5 is excluded.
The interval contains all real numbers between 2 and 5, $2\leq x \lt 5$
