Which equation demonstrates the Inverse Property, where a plus its opposite equals zero?

• A. a * (1/a) = 1
• B. a + (-a) = 0
• C. a - a = 0
• D. a + a = 2a

Answer: (B)

The additive inverse property says that every number has an opposite that, when added to it, makes zero. The way to see this directly is with a + (-a) = 0, since -a is the opposite of a and adding them cancels out to zero. This is the clearest way to express that idea: a plus its opposite equals zero.

For comparison, a - a = 0 also reflects the cancellation idea because subtracting a from itself removes the value, leaving zero, but it’s framed in terms of subtraction rather than adding the opposite. The expression a + a = 2a simply doubles a and doesn’t involve canceling with an opposite. The expression a * (1/a) = 1 is about the multiplicative inverse, not the additive inverse.