Respostas

2014-01-03T10:01:52-02:00
A) -2A:
| -2  4  0|
|-10 8 -6|

b) 1/3 B:
|-1 2 4|
|3 -2 5|

c) 1/2.(A+B)
A + B = |1-3..-2+6..0+12|
.............|5+9..-4-6..3+15|

A + B = |-2    4  12|
.............|14 -10 18|

1/2.(A+B):
|-1  2  6|
| 7  -5 9|
1 5 1