Final answer:
The property used in the equation 91 - 0 = 91 is the Identity Property of Addition.
Step-by-step explanation:
The property that we are using in the equation 91 - 0 = 91 is the Identity Property of Addition.
This property states that when we add zero to any number, the sum is always that number itself.
In this case, adding zero to 91 does not change its value, so the sum is still 91.
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