a 11 a 12 a 1 r a 21 a 22 a 2 r ⋮ a r 1 a r 2 a r r {\displaystyle {\begin{matrix}a_{11}&a_{12}&a_{1r}\\a_{21}&a_{22}&a_{2r}\\\vdots \\a_{r1}&a_{r2}&a_{rr}\\\end{matrix}}} a 1 , r + 1 … a 1 r a 2 , r + 1 … a 2 r ⋮ a r , r + 1 … a r r {\displaystyle {\begin{matrix}a_{1,r+1}&\dots &a_{1r}\\a_{2,r+1}&\dots &a_{2r}\\\vdots \\a_{r,r+1}&\dots &a_{rr}\\\end{matrix}}} a r + 1 , r a r + 1 , r a 1 r a 1 , r + 1 … a r + 1 , n ⋮ a m 1 a m 2 a m r a m , r + 1 … a m n {\displaystyle {\begin{matrix}a_{r+1,r}&a_{r+1,r}&a_{1r}&a_{1,r+1}&\dots &a_{r+1,n}\\\vdots \\a_{m1}&a_{m2}&a_{mr}&a_{m,r+1}&\dots &a_{mn}\\\end{matrix}}}
a 11 a 12 a 1 r a 1 , r + 1 … a 1 r a 21 a 22 a 2 r a 2 , r + 1 … a 2 r ⋮ ⋮ a r 1 a r 2 a r r a r , r + 1 … a r r a r + 1 , r a r + 1 , r a 1 r a 1 , r + 1 … a r + 1 , n ⋮ a m 1 a m 2 a m r a m , r + 1 … a m n {\displaystyle {\begin{matrix}a_{11}&a_{12}&a_{1r}&a_{1,r+1}&\dots &a_{1r}\\a_{21}&a_{22}&a_{2r}&a_{2,r+1}&\dots &a_{2r}\\\vdots &&&\vdots \\a_{r1}&a_{r2}&a_{rr}&a_{r,r+1}&\dots &a_{rr}\\a_{r+1,r}&a_{r+1,r}&a_{1r}&a_{1,r+1}&\dots &a_{r+1,n}\\\vdots \\a_{m1}&a_{m2}&a_{mr}&a_{m,r+1}&\dots &a_{mn}\\\end{matrix}}}