1,were lived

2, drinking

3, has lived 

4, go

5, bought

6, haven't seen

7, was studied

ông gửi tách ra dài vcl 

75b

76c

77a

78a

79d

80c

6a

7d

8c

9c

10d

11d

12a

13c

14b

15b

a, 6x³y²+12x²y-8xy

=2xy(3x²y+6x-4)

n_ZnO=8,1:81=0,1(mol)

PTHH Zn+O₂-->ZnO

=>n_Zn=n_ZnO=0,1 mol

=>m_Zn=0,1 x 65 = 6,5 (g)

16a

17a

18c

19d

20c

6a

7b

8d

9a

10a

11c

12b

13b 

14d

15c