Write down the additive inverses of :
9

Answer

To find the additive inverse of the number 9, we can follow these steps:

### Step 1: Understand the Concept of Additive Inverse
The additive inverse of a number is the value that, when added to the original number, results in zero.

### Step 2: Set Up the Equation
Let’s denote the additive inverse of 9 as \( x \). According to the definition, we can write the equation:
\[ x + 9 = 0 \]

### Step 3: Solve for \( x \)
To find \( x \), we need to isolate it on one side of the equation. We can do this by subtracting 9 from both sides:
\[ x = 0 - 9 \]
\[ x = -9 \]

### Step 4: Conclusion
Thus, the additive inverse of 9 is \( -9 \).

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