Final answer:
The property being described in the equation x = x is called the reflexive property. This property states that any quantity is equal to itself.
Step-by-step explanation:
The property being described in the equation x = x is called the reflexive property.
The reflexive property states that any quantity is equal to itself. In this case, the variable x is being compared to itself, so the equation is always true. This can be seen with the example given: 10 = 10.
This property is an important part of mathematical reasoning and is often used in algebra to simplify equations and solve problems.