Question

dada as matrizes A =123, B=-7-8 9, C=23-4

Answer 1

..........|1....2..3|1.....2
..........|-7.-8..9|-7..-8
..........|2...3.-4|2....3

=> (1x-8x-4) + (2x9x2) + (3x-7x2) - (2x-8x3) - (3x9x1) - (-4x-7x2)

=>(-8x-4) + (18x2) + (-21x2) - (16x3) - (27x1) - (24x2)

=> 32 + 36 + (-42) - (-48) - (27) - (48)

=> 32 + 36 - 42 + 48 - 27 - 48

=> 68 - 52 + 48 - 27 - 48

=> 26 + 48 - 27 - 48

=> 74 - 27 - 48

=> 47 - 48

=> - 1