Final answer:
The additive inverse of a rational number is found by changing its sign.
Step-by-step explanation:
The additive inverse of a rational number is the number that, when added to the original number, results in a sum of zero. To find the additive inverse of a rational number, we simply change the sign of the number.
For example, the additive inverse of -1/2 is 1/2, because (-1/2) + (1/2) = 0. The additive inverse of 0.25 is -0.25, because 0.25 + (-0.25) = 0. Similarly, the additive inverse of 9 is -9, the additive inverse of 10 is -10, and the additive inverse of -0.4 is 0.4.
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