#### Answer

Set-builder notation:
$\left\{x | x \le -1\right\}$
Graph:

#### Work Step by Step

An infinity on the left end means all the numbers to the left are included in the set.
A bracket beside $-1$ means $-1$ is included in the set.
Thus, in inequality notation, the set is $x \le -1$.
In set-builder notation, this can be written as:
$\left\{x | x \le -1\right\}$
To graph the set on a number line, plot a solid dot at $-1$ then shade the region to its left (refer to the attached image in the answer part above).