Final answer:
The property being demonstrated in the equation is the commutative property of addition.
Step-by-step explanation:
This question is about the property of addition called the commutative property. According to this property, the order of the numbers being added does not affect the sum. In the given equation 2 + x + 10 = 2 + 10 + x, we can rearrange the terms on the left side to get x + 12 = 12 + x. This demonstrates the commutative property of addition, which states that the sum of two or more numbers remains the same even if the order of the numbers is changed.
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