1:

4:

a: \(B=\dfrac{x-x+\sqrt{x}}{\sqrt{x}-1}=\dfrac{\sqrt{x}}{\sqrt{x}-1}\)

Khi x=9/25 thì B=3/5:(3/5-1)=3/5:(-2/5)=-3/2

b: \(A=\dfrac{x-1+\sqrt{x}+2-x}{x-\sqrt{x}}=\dfrac{\sqrt{x}+1}{x-\sqrt{x}}\)

c: P=B:A

\(=\dfrac{\sqrt{x}}{\sqrt{x}-1}\cdot\dfrac{\sqrt{x}\left(\sqrt{x}-1\right)}{\sqrt{x}+1}=\dfrac{x}{\sqrt{x}+1}\)

P nguyên

=>x-1+1 chia hết cho căn x+1

=>căn x+1 thuộc Ư(1)

=>căn x+1=1 hoặc căn x+1=-1

=>căn x=-2(loại) hoặc căn x=0(loại)

1 send - will receive 

2 do - will improve

3 find - will give

4 will go - has

5 will go- gets

6 doesn't phone - will leave

7 don't study - won't pass

8 rains - won't have to

9 won't be able - watch

10 can't move - isn't

11 study - will pass

1B
2C
3C
4D
5A
6C
7C
8C
9C
10B
11C
12A
13B
14a
15A
16B
17A
18A

C C C D A C C A C B C B B C A B D A

I.

1.D

2.C

3.C

II.

4.C

5.A

D

C

A

C

A

Câu 1. B

Câu 2. C

Câu 3. C

Câu 4. A

Câu 5. B

Câu 6. C

Câu 7. A

Câu 8. D