> with(linalg):
Warning, the protected names norm and trace have been redefined and
unprotected

> b:=matrix(3,6,[[-3,0,3,0,0,0],[0,-2,0,-2,0,4],[-2,-3,-2,3,4,0]]);

                     [-3     0     3     0    0    0]
                     [                              ]
                b := [ 0    -2     0    -2    0    4]
                     [                              ]
                     [-2    -3    -2     3    4    0]

> d:=matrix(3,3,[[1,3/10,0],[3/10,1,0],[0,0,7/20]]);

                          [ 1      3/10     0  ]
                          [                    ]
                     d := [3/10     1       0  ]
                          [                    ]
                          [ 0       0      7/20]

> k:=multiply(transpose(b),d,b);

            [          39                -3                   ]
            [52/5      --      -38/5     --     -14/5    -18/5]
            [          10                10                   ]
            [                                                 ]
            [ 39       143               17                   ]
            [ --       ---     3/10      --     -21/5     -8  ]
            [ 10       20                20                   ]
            [                                                 ]
            [                           -39                   ]
       k := [-38/5    3/10     52/5     ---     -14/5    18/5 ]
            [                           10                    ]
            [                                                 ]
            [ -3       17       -39     143                   ]
            [ --       --       ---     ---     21/5      -8  ]
            [ 10       20       10      20                    ]
            [                                                 ]
            [-14/5    -21/5    -14/5    21/5    28/5       0  ]
            [                                                 ]
            [-18/5     -8      18/5      -8       0       16  ]

> K:=(3*2100/91/144)*evalm(k);

             [          39                -3                   ]
             [52/5      --      -38/5     --     -14/5    -18/5]
             [          10                10                   ]
             [                                                 ]
             [ 39       143               17                   ]
             [ --       ---     3/10      --     -21/5     -8  ]
             [ 10       20                20                   ]
             [                                                 ]
          25 [                           -39                   ]
     K := -- [-38/5    3/10     52/5     ---     -14/5    18/5 ]
          52 [                           10                    ]
             [                                                 ]
             [ -3       17       -39     143                   ]
             [ --       --       ---     ---     21/5      -8  ]
             [ 10       20       10      20                    ]
             [                                                 ]
             [-14/5    -21/5    -14/5    21/5    28/5       0  ]
             [                                                 ]
             [-18/5     -8      18/5      -8       0       16  ]

> K:=(5/208)*evalm(%*208/5);

                  [ 208      78    -152      -6    -56     -72]
                  [                                           ]
                  [  78     143       6      17    -84    -160]
                  [                                           ]
                  [-152       6     208     -78    -56      72]
       K := 5/208 [                                           ]
                  [  -6      17     -78     143     84    -160]
                  [                                           ]
                  [ -56     -84     -56      84    112       0]
                  [                                           ]
                  [ -72    -160      72    -160      0     320]

> 
