(1)转置后秩不变 (2)r(A)<=min(m,n),A是m*n型矩阵 (3)r(kA)=r(A),k不等于0 (4)r(A)=0 <=> A=0 (5)r(A+B )<=r(A)+r(B ) (6)r(AB )<=min(r(A),r(B )) (7)r(A)+r(B )-n<=r(AB )