14, the determinant of the matrix is equal to the product of eigenvalues, and the eigenvalue of 4A- 1-E can be obtained. The eigenvalue of A- 1 is the reciprocal of the eigenvalue of a, so the eigenvalue of 4A- 1 -E is 4/1= 3,4/2-1=1,4/3-/.

Another method is to assume that A is a diagonal matrix diag( 1, 2,3) and substitute it for calculation.

1 1, I think there is something wrong with this topic. Known conditions only indicate the number of unknowns, and the number of equations is unknown. Only c is correct. Looking at the four options, the answer means that the number of equations is n, which is debatable.

10. First of all, there is only a vector of n-(n- 1)= 1 in the basic solution system of Ax=0, and α 1-α2 is a non-zero solution, so the answer is D.

16, indicating that the sum of elements in each row is zero, (1, ..., 1)' is the solution, and there are only 1 vectors in the basic solution system, so the general solution is k (1,/kloc).