Question

Use interval notation to express the following: The set of all numbers less than or equal to −5.

Answer 1

(- infinitysymbol,-5]

see image.

Explanation:

Interval notation uses parenthesis or square brackets in the format:

( or [ begin , end )or]

Always use parenthesis around the infinity or negative infinity symbol. Square brackets are for when the number is included. Like in this case where it says "or equal to -5"

see image.