Respuestas

2013-08-30T20:27:03+02:00
8 - 9 x [ -4 x 21 - 3 x ( -13)] -2 x 4
8 - 9 x [ -84 + 39] - 8
8 - 9 x [ - 45] - 8
8 + 405 - 8  
413 - 8
405

2013-08-30T21:03:32+02:00
8 - 9x [ -4 x 21 - 3 x (-13)] - 2 x 4
8 - 9 x [-84 +39] - 8
8 - 9 x [-45] - 8
8+ 405 - 8
413- 8
405