1. Calculate $\frac{45.1^{3}-13.9^{3}}{31.2}+45.1 \times 13.9$ The value equals $\qquad$ .
$\begin{array}{l} \text { II.1.3 481. } \\ \frac{45.1^{3}-13.9^{3}}{31.2}+45.1 \times 13.9 \\ = \frac{(45.1-13.9)\left(45.1^{2}+45.1 \times 13.9+13.9^{2}\right)}{45.1-13.9}+ \\ 45.1 \times 13.9 \\ = 45.1^{2}+2 \times 45.1 \times 13.9+13.9^{2} \\ =(45.1+13.9)^{2}=59^{2}=3481 .\end{array}$