Evaluate the following :
`|-12|+|-9|`.

Answer

To evaluate the expression `|-12| + |-9|`, we will follow these steps:

### Step 1: Understand the Modulus
The modulus (or absolute value) of a number is its distance from zero on the number line, regardless of direction. This means that the modulus of any negative number will be a positive number.

### Step 2: Calculate the Modulus of -12
We need to find the modulus of -12:
\[ |-12| = 12 \]

### Step 3: Calculate the Modulus of -9
Next, we find the modulus of -9:
\[ |-9| = 9 \]

### Step 4: Add the Results
Now, we add the results from Step 2 and Step 3:
\[ 12 + 9 = 21 \]

### Final Answer
Thus, the value of `|-12| + |-9|` is:
\[ \boxed{21} \]

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