Write the interval notation corresponding to the set notation

Question

{x | x < –7}

Could it be (-7]

Answer 1

The simple interval notation requires the lower and upper limites separated by a comma. Also, parenthese indicate the limites are excluded.
So the example given will be translated to
(-infinity, -7)
One or more square brackets will replace the parenthesis if the limit is included.
For example, [-5,5] will start from -5 inclusively to +5, also inclusively.
Simple intervals may be joined together using the logical 'and' or 'or' operators.
See:
http://www.sosmath.com/algebra/inequalities/ineq02/ineq02.html

Answer 2

Thank you for your help!