40
45

b
c
b

c
b

1g
2d
3h
4b
5a
6e
7c
8f

a)
\(16x^2-\left(4x-5\right)^2=15\)
\(\left(4x-4x+5\right)\left(4x+4x-5\right)=15\)
\(5\left(8x-5\right)=15\)
40x-25=15
40x=40
x=1

 

1a
2a
3b
4a
5b
6a
7c
 

chiều rộng hình chừ nhật là
490:7=70cm
chiều dài hình chữ nhật là
490:2-70=175cm
diện tích hình chữ nhật là
175x70=12 250 cm²

6,it take us 10 hours to arrive to the camping site
7. cars is expensive  than motorbikes
8. george will be here with us tomorrow
9. walking in rain give my brother pleasure
10. If  it rain tomorrow  ,I will stay at home
11 I suggest organizing  a show raise  money
13It take me one hour to go  school  every morning 

chiều rộng vườn hoa là
36:2-11=7m
diện tích vườn hoa là
11.7=77m²

1. Fred wouldn’t do that if he didn’t have your permission.

   Unless he had your permission,Fred wouldn’t do that

2. If you don’t leave immediately, I will call a policeman.

   Unless you leafes immediately, I will call a policeman.

3. We won’t have a holiday because we don’t have enough money.

   If we had enough money,we would have a holiday 

4. I don’t know the answer, so I can’t tell you.

   If I knew the answer, I could tell you.

5. If you didn’t agree with him, Charrles wouldn’t even suggest it.

    Unless you agreed with him, Charrles wouldn’t even suggest it.

6. If you study harder, you are going to pass the exam.

    Unless you study harder,you won't pass the exam

7. I wouldn’t have believed it if I hadn’t seen it with my own eyes.

    Unless I had seen it with my own eyes, I wouldn’t have believed 

8. Go to bed early or you will be tired the next morning.

    If you go to bed early , you won't be tired the next morning.

9. Without the map, we would  have got lost.

    If it had had the map, we wouldn't  have got lost.