简答题:设n阶矩阵A满足A²+2A一4E=0，证明A可逆，并求A．

A 0 B 2 C -2 D 12

A <img src="https://www.beizhujiaoyu.com/uploads/202208/1612580876741.png" width="73" height="80" />  B <img src="https://www.beizhujiaoyu.com/uploads/202208/161258088371441.png" width="73" height="80" />  C <img src="https://www.beizhujiaoyu.com/uploads/202208/161258088841901.png" width="73" height="80" />  D <img src="https://www.beizhujiaoyu.com/uploads/202208/161258089744341.png" width="72" height="81" /> 

A λE-A=λE-B B |A|=|B| C |λE-A|=|λE-B| D r(A)=r(B)

A -E B E C D D A

A 1 B 2 C 3 D 4