////////////////////////////////////////////////////////////////
//
//     http://www.planetquantum.com/Solve/Level1/Den13/Page12.txt
//
////////////////////////////////////////////////////////////////

Generator:
(C (Cot 1) (Tan 1) 6 7 3)

Problem:
(= (cdot #[[642 92 615 934 330 703 6]
           [419 986 594 265 620 230 278]
           [113 918 171 379 101 162 280]
           [426 276 856 839 164 672 198]
           [482 919 760 196 804 658 143]
           [65 960 471 415 739 183 569]]
         #[[x_1] [x_2] [x_3] [x_4] [x_5] [x_6] [x_7]])
   #[[155] [740] [772] [465] [490] [223]])

Solution:
(= #[[x_1] [x_2] [x_3] [x_4] [x_5] [x_6] [x_7]]
   #[[20021875850118601]
     [-5913665750292769]
     [-10012779725044685]
     [-12321716859616369]
     [-6843572338715221]
     [10571855702242934]
     [30453390689033885]])