 1 3 0 1 3 1 ...0,25X X X D        3 9 0 1 3X X ...

Câu 6.

 

1 3 0 1 3 1 ...0,25

x x x d

       

 

3 9 0 1 3

x x

 

  



3

; ...0,25 1

 

D d

   

 