=\(2x-\)\(\dfrac{1}{4}y^2-4y\)

D

Unit 5:

1.C

2.B

3.C

4.D

5.B

Unit 6:

1.A

2.C

3.D

4.B

5.B

C

A

A

D

(x+y)(x−y)−x.(x+1)=\(x^2-y^2-x^2-x=-y^2-x\)

Chúc bạn học tốt

1.D 

2. D

3.C

4.A

5.B

6.C

7.C

8. A

9. A. 

10.C

1 used to smoke

2 used to be

3 didn't use to drink

4 used to have

5 didn't use to like

6 used to live

7 used to play

8 didn't use to

Chúc bạn học tốt!