chap 6

1 chap |-1|=1 

2 chap 2 

3 chap 3 

4 chap |(-1) +(-3) | 

5 chap5 

6 chap 6 

7 chap √49 +0+5²-30 

8 ∆ABC cân tại A ; A=164 , B=C=? 

9 chap 9 

10 chap 10000000000000000 

11 chap 11 

12 chap 12 :D 

13 chap 20+20+20+7-54 

14 chap 14: vỏ bọc bên ngoài? 

15 chap 15 

16 chap 16 

17 chap 17 

18 chap 18- Ai xuyên nữa? 

19 chap 19 

20 chap 20 

21 chap 21 

22 chap 22 

23 chap 23 