S S X X X D 64 .● 1 2 4 2 3 4( 0,5Đ ) 3 300X K K2 64●...
Câu 2
S S x x x
d 64 .
●
1
2
4
2
3
4
( 0,5đ )
3 3
0
x k k
2 64
●
1
4
2
3
4
d 4 .
S x k x kx k
3
k
3 3
k
0,25đ
1 2 64 32
S S S S S k k k
Theo giả thiết
1
2
1
1
2
2 4 3 3 3
0
4
3
2
2 k k 12 k 32 0
t
k
t