设A为2级方阵: <img class=jc-formula data-tex=\left| A \right| =2 src=https://huaweicloudobs.ahjxjy.cn/5F65A17F49C328743182B3A80206DC87.png style=vertical-align: middle;/>,则<img class=jc-formula data-tex=\left| -2A \right| src=https://huaweicloudobs.ahjxjy.cn/D4D919815DF8BCB061EDD64451FBDA82.png style=vertical-align: middle;/>=[填空].