Evaluate `: 32.9 - 75.5 div 2.5 + 16.1 xx 0.3 + 4.5`

Answer

To solve the expression \( 32.9 - 75.5 \div 2.5 + 16.1 \times 0.3 + 4.5 \), we will follow the order of operations, often remembered by the acronym BODMAS (Brackets, Orders, Division and Multiplication, Addition and Subtraction).

### Step-by-step Solution:

1. **Identify the operations**: The expression contains subtraction, division, multiplication, and addition.

2. **Perform the division first**:
\[ 75.5 \div 2.5 \]
To simplify, we can convert the division into a fraction:
\[ \frac{75.5}{2.5} = \frac{755}{25} \quad (\text{Multiplying numerator and denominator by 10}) \]
Now, perform the division:
\[ 755 \div 25 = 30.2 \]

3. **Rewrite the expression**: After performing the division, we rewrite the expression:
\[ 32.9 - 30.2 + 16.1 \times 0.3 + 4.5 \]

4. **Perform the multiplication**:
\[ 16.1 \times 0.3 \]
To multiply:
\[ 16.1 \times 0.3 = 4.83 \]

5. **Rewrite the expression again**: Now, we have:
\[ 32.9 - 30.2 + 4.83 + 4.5 \]

6. **Perform the subtraction**:
\[ 32.9 - 30.2 = 2.7 \]

7. **Add the results**:
\[ 2.7 + 4.83 + 4.5 \]
First, add \( 2.7 + 4.83 \):
\[ 2.7 + 4.83 = 7.53 \]
Now add \( 7.53 + 4.5 \):
\[ 7.53 + 4.5 = 12.03 \]

### Final Answer:
The final result of the expression \( 32.9 - 75.5 \div 2.5 + 16.1 \times 0.3 + 4.5 \) is:
\[ \boxed{12.03} \]