Step 1: Identify Priority Operations

According to the BODMAS rule, perform multiplication ($4.2 imes 3 = 12.6$) and division ($\frac{5.6}{2} = 2.8$) before addition and subtraction.

$4.2 imes 3 = 12.6, \quad \frac{5.6}{2} = 2.8$

Step 2: Substitute Values

Substitute the computed multiplication and division results back into the expression.

$12.5 + 12.6 - 2.8 + 10.4$

Step 3: Evaluate Addition and Subtraction

Add the positive terms together: $12.5 + 12.6 + 10.4 = 35.5$. Subtract the negative term: $35.5 - 2.8 = 32.7$.

$35.5 - 2.8 = 32.7$