1 C

2 A

3 C

4 B

1 A

2 B

3 D

4 A

12 differences

13 different

14 has demonstrated

15 demonstration

16 demonstrate - difficult

17 educative

18 determination

19 oppositively

20 oppositive

lỗi rồi

1 D

2 A

3 C

4 D

5 A

6 B

7 B

8 A

9 C

10 A

15 C

16 A

17 C

18 A

19 A

20 D

1 he didn't have to study for his exam

2 she weren't lazy, she could pass the exam

3 If my brother had left the car keys, I could have picked him up at the station

4 he pays me tonight, I will have enough money to buy a car

5 he didn't smoke too much, he could get rid of his cough

6 I hadn't lost my key, I wouldn't have had to pound on the door.....

7 she weren't shy, she would enjoy the party

8 I get a work permit, I will stay for another month

9 he took some exercises, he wouldn't be so unhealthy

10 those people had been prepared  to face the floods, the consequence wouldn't have been disastrous

11 she starts working hard now, she won't be able to pass the final test

12 you are patient, you won't get success

13 somebody waters these flowers. they will die

14 it doesn't stop raining, we won't go out

15 hhe hadn't drunk alcohol, he would have passed the contest

Câu 1:

a)2x-3=5

\(\leftrightarrow\)2x=5+3

\(\leftrightarrow\)2x=8

\(\leftrightarrow\)x=4

Vậy pt có tập nghiệm S={4}

b)(2x+1)(x-3)=0

\(\leftrightarrow\) 2x+1=0

Hoặc x-3=0

\(\leftrightarrow\)x=-1/2

x=3

Vậy pt có tập nghiệm S={-1/2;3}

d)3x-4=11

\(\leftrightarrow\)3x=11+4

\(\leftrightarrow\)3x=15

\(\leftrightarrow\)x=5

Vậy pt có tập nghiệm S={5}

e)(2x-3)(x+2)=0

\(\leftrightarrow\)2x-3=0

Hoặc x+2=0

\(\leftrightarrow\)x=3/2

hoặc x=-2

Vậy pt có tập nghiệm S={3/2;-2}

Câu 2:

a)2x-3<15

\(\leftrightarrow\)2x<15+3

\(\leftrightarrow\)2x<18

\(\leftrightarrow\)x<9

Vật bpt có tập nghiệm S={x|x<9}

c)5x-2<18

\(\leftrightarrow\)5x<20

\(\leftrightarrow\)x<4

Vậy bpt có tập nghiệm S={x|x<4}

Mấy bài phân số nhác gõ quá~