a1=(1,-1,2,4),a2=(0,3,1,2),a3=(3,0,7,14),a4=(1,-1,2,0),a5=(2,1,5,6)这组向量的秩是多少?

(α1,α2,α3,α4,α5)=
1 0 3 1 2
-1 3 0 -1 1
2 1 7 2 5
4 2 14 0 6
r2+r1,r3-2r1,r4-4r1
1 0 3 1 2
0 3 3 0 3
0 1 1 0 1
0 2 2 -4 -2
r2-3r3,r4-2r3
1 0 3 1 2
0 0 0 0 0
0 1 1 0 1
0 0 0 -4 -4
R(A) = 3.