Question

Write the set of all integers less than -20 in set-builder notation.
The set-builder notation is {x|x EZ and

1. thienthanh
{ x ∈ Z | x < -20 }
Step-by-step explanation:
Set-builder notation is used in math to describe a set by saying what properties its members have.
It uses curly brackets called “braces”.
The first part after the first curly bracket tells you what set of numbers x belongs to.
The ∈ symbol means “is an element of”.
For example:
• x ∈ N  means “x is an element of the set of Natural numbers”.
• x ∈ Z  means “x is an element of the set of Integers”.
• x ∈ R  means “x is an element of the set of Real numbers”.
This is followed by “|” or “:” which means “such that”.
This is then followed by the conditions of x, for example:
• x < 2  means “x is less than 2”.
• -1 < x < 1  means “x is greater than -1 and less than 1”.
Therefore, to write the set of all integers less than -20 in set-builder notation:
• { x ∈ Z | x < -20 }
This means:  “The set of all x’s that are a member of the Integers, such that x is less than -20”