A set X consists of all real numbers greater than or equal to 1. Use set-builder notation to define X.

We know that

The standard form of set-builder notation is

x

This set-builder notation can be read as "the set of all x such that x (satisfies the condition) ".

In this problem, there are 2 conditions that must be satisfied:

1st: x must be a real number

In the notation, this is written as "x ε R".

Where ε means that x is "a member of" and R means "Real number"

2nd: x is greater than or equal to 1

This is written as "x ≥ 1"

therefore

Combining the 2 conditions into the set-builder notation:

X = x

the answer is

X = x ε R and x ≥ 1