It is the third option: {1, 2, 3}
In order to solve you get x by itself:
5-x=12
-5 -5
-x=7
divide by negative 1
1/5 equals 12 so 12 times 5 is 60 so
a=36
b=24
Your welcome
The property applied is the associative property
<h3>Algebraic properties</h3>
There are several algebraic properties in mathematics; each of which have their own applications
Some of these properties are:
- Commutative
- Distributive
- Associative
- Identity
The mathematical expression is given as:

And it is calculated as follows:


The property applied above is the associative property
Read more about mathematical properties at:
brainly.com/question/10628093
5/9 is equal to.5555555555