A=[1 1 5; 2 1 4]
B=[1 1 1 0; 1 2 -1 5; -2 6 4 2]
C=[2 3 10; -2 -3 5]
D=[1 1 -1 10; -2 3 3 11; -3 7 5 32]
E= [ 1 1 1 0 -1 2 3;
     5 5 -10 2.5 1 -4 3.1;
     2 3 4 5 6 7 8;
     0 -2.1 3.7 6 2 4 5 ]









