=a=0,r=0.b=0,a≠0,r=4.以下设 b≠0
A∽(a-3b,a+3b,a+3b,a+3b b,a,b,b b,b,a,b b,b,b,a)
①a+3b≠0 A∽(1,1,1,1 0,a-b,0,0 0,0,a-b,0 0,0,0,a-b)
a=b时,r=1.a≠b时,r=4.
②a+3b=0 A∽(0,0,0,0 1,a/b,1,1 0,b-a.a-b,0 0,0,b-a.a-b),r=3.
[此时必有a≠b,否则a+3b=4b=0,b=0,不可,]
=a=0,r=0.b=0,a≠0,r=4.以下设 b≠0
A∽(a-3b,a+3b,a+3b,a+3b b,a,b,b b,b,a,b b,b,b,a)
①a+3b≠0 A∽(1,1,1,1 0,a-b,0,0 0,0,a-b,0 0,0,0,a-b)
a=b时,r=1.a≠b时,r=4.
②a+3b=0 A∽(0,0,0,0 1,a/b,1,1 0,b-a.a-b,0 0,0,b-a.a-b),r=3.
[此时必有a≠b,否则a+3b=4b=0,b=0,不可,]