设矩阵A=[(1,-3,1);(0,1,1);(1,-2,-2);(0,2,a)],B是3阶非零矩阵,且AB=0,则a=?

问题描述:

设矩阵A=[(1,-3,1);(0,1,1);(1,-2,-2);(0,2,a)],B是3阶非零矩阵,且AB=0,则a=?
A=
1 -3 1
0 1 1
1 -2 -2
0 2 a

a=2