设<img class=jc-formula data-tex=A src=https://huaweicloudobs.ahjxjy.cn/53F870B8D448BB3DB08A67264B6329F9.png style=vertical-align: middle;/>为3阶方阵, 且<img class=jc-formula data-tex=\left| A \right| =\frac { 1 }{ 2 } src=https://huaweicloudobs.ahjxjy.cn/3CE387C18674F973BEC9D0486E9CA68F.png style=vertical-align: middle;/>,则<img class=jc-formula data-tex=\left| { 3A }^{ -1 }-2{ A }^{ \ast } \right| = src=https://huaweicloudobs.ahjxjy.cn/C0983C0F70DAF4841731EFEBAF3C799B.png style=vertical-align: middle;/>[填空].