Page 35 - Past Year

33 | P a g e

1  1 
 4 2 0 
   1 2 0


1
6. (a) A   3 1 1  (b) X   3 2 1
 4 2 4   
    2 4 1 
 1 1 1 
  2 4 

7. (a) p = 6, q = –4

(b) (i) A   2

(ii) p = –2 ,q = 1

 5 1 
5  4 1     2 2  2  


-1
(iii) adjA =   2 2  2  ; A =  1  1 1 
   
 3  2 1    3 1  1 
 2 2 

 4 1 4 
   
1 0 0   5 5 5 


-1
8. (a) AB= 5  0 1 0  ; A =    1  1 7  
  5 5 10
 0 0 1   
  1 1  1  
 5 5 5 
(b) (i) x + 2y +3z = 20

4z = x

2y + 2z = 10
 1 2  3  x    20
 



(ii)  1 0 4   y  = 0


     
 0 2 2   z   10 
(iii) x = 8, y = 3, z = 2

 0 2  3
 
9. (a)  3 0 2 (b) –Refer to Lecturer–

  2 1  1 