Step-by-step explanation:
I don't understand the question
Answer: the answer is 2
Step-by-step explanation:
<span>-(-7-9-20)+(-3+11-21)
= 7 + 9 + 20 - 3 + 11 - 21
= 47 - 24
= 23</span>
Interval simply represent the set of numbers containing all numbers between any two numbers.
The representations of
are
and 
From the question, we have:
![(-\infty, -6]](https://tex.z-dn.net/?f=%28-%5Cinfty%2C%20-6%5D)
The above representation is in interval notation.
The interpretation is that;
The highest number in the interval is -6
The equivalent using set notation is:

The equivalent using inequalities is:

Read more about intervals at:
brainly.com/question/17249352