Abstract: By applying the matrix rank method, in this note, the general expressions of the common least-square solutions to the matrix equations AX = C,XB = D is deduced,the extremal ranks of the common least-square solutions is obtained.

• 文摘:通过使用矩阵秩方法；我们给出了矩阵方程组AX=C；XB=D的公共最小二乘解的通解表达式；以及公共最小二乘解的极大秩和极小秩.