12. 能简便的用简便方法计算。
$5\sqrt{13}×4×2\sqrt{13} \quad (2\sqrt{13}=2×\sqrt{13}) \quad \quad \quad \quad \quad \quad 2\sqrt{2}-\sqrt{2}+10\sqrt{2}$
$(-\dfrac{1}{2})×(-\dfrac{2}{3})×(-\dfrac{3}{4})×(-\dfrac{4}{5}) \quad \quad \quad \quad \quad \quad -3^2×(-3)^2$

520 $11\sqrt{2}$ $\dfrac{1}{5}$ $-81$