`21-12-:3xx2`

Answer

To solve the expression \( 21 - 12 \div 3 \times 2 \), we will follow the order of operations, often remembered by the acronym PEMDAS/BODMAS (Parentheses/Brackets, Exponents/Orders, Multiplication and Division (from left to right), Addition and Subtraction (from left to right)).

### Step-by-step Solution:

1. **Identify the operations**: The expression has subtraction, division, and multiplication. According to the order of operations, we will perform division and multiplication before subtraction.

2. **Perform the division**:
\[ 12 \div 3 = 4 \]
Now, replace \( 12 \div 3 \) in the expression:
\[ 21 - 4 \times 2 \]

**Hint**: Always perform division and multiplication before subtraction.

3. **Perform the multiplication**:
\[ 4 \times 2 = 8 \]
Now, replace \( 4 \times 2 \) in the expression:
\[ 21 - 8 \]

**Hint**: After division, the next step is to handle multiplication.

4. **Perform the subtraction**:
\[ 21 - 8 = 13 \]

**Hint**: Finally, subtract the result from the previous step from the first number.

### Final Answer:
The result of the expression \( 21 - 12 \div 3 \times 2 \) is \( 13 \).