4.利用矩阵的初等行变换,求下列方阵的逆阵:-|||-(1) (} 1& 2& -1 3& 4& -2 5& -4& 1 ) .

7.求下列矩阵的逆.-|||-1 2-|||-(1) ;-|||-2 5-|||-(2) (} 1& 2& -1 3& 4& -2 5& -4& 1 ) .

(16)设 D= |} 1& 2& 3& 4 2& 3& 4& 1 3& 4& 1& 2 4& 1& 2& 3= __ ;

4.试利用矩阵的初等变换,求下列方阵的逆阵:-|||-(1) (} 3& 2& 1 3& 1& 5 3& 2& 3 ) .

(} -4& 2& -1 4& -1& 2 3& -1& 1 ) .的逆矩阵。（ ）A 对B 错是矩阵的逆矩阵。（）A对B错

用初等变换法求矩阵A= (} 1& 2& 3 2& 2& 1 3& 4& 3 -

3.设 |A|= |} 1& 2& 1& 1 2& 3& 4& 8 3& 4& 9& 27 4& 1& 16& 64 ,其中Aiy为元素aiy的代数-|||-

11.设 D= |} 3& -5& 2& 1 1& 1& 0& -5 -1& 3& 1& 3 2& -4& -1& -3

11.设 D= |} 3& -5& 2& 1 1& 1& 0& -5 -1& 3& 1& 3 2& -4& -1& -3

5.设 D= |} 1& 2& 3& 4 -2& 4& 7& 0 3& 1& 2& 5 1& 1& 1& 1= __

矩阵A= (} 1& -1& 2& -1 3& 1& 0& 2 1& 3& -4& 4 ) .的秩r(A) =___矩阵的秩r(A)=___