Final answer:
The opposite of a positive number is always negative because multiplication and division rules for sign indicate that different signs yield a negative result. Zero is its own opposite because adding or subtracting zero does not change the value of the number.
Step-by-step explanation:
In Mathematics, the opposite of a positive number will always be a negative number because the multiplication and division rules for sign indicate that when two numbers with different signs are multiplied or divided, the answer will have a negative sign.
For example, when a positive number is multiplied by a negative number, the result is always negative. Similarly, when a negative number is divided by a positive number, the result is always negative.
On the other hand, zero is its own opposite number because when you add zero to a number or subtract zero from a number, the result is always the same as the original number. Zero has no positive or negative value.