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

5: \(=\dfrac{1}{2}\cdot10-\dfrac{1}{2}=\dfrac{1}{2}\cdot9=\dfrac{9}{2}\)

1 are

2 am

3 is

4 are

5 are

6 are

7 is

8 is

9 is

10 are

IV

1 is writing

2 are losing

3 is having

4 is staying

5 am not lying

6 is always using

7 are having

8 Are you playing

9 are not touching

10 Is - listening

11 Is- winning

12 am not staying

13 is not working

14 is not reading

15 isn't raining

16 am not listening

17 Are they making

18 Are you doing

19 Is - sitting

20 is - doing

21 are-putting

22 are-wearing

23 is-studying

2, am

3, is

4,are

5,are

6,are

7,is

8,is

9,is

10,are

IV

1,2,7 OK

3,is having

4,has stayed

5,am not lying

6,always uses

8,Are-playing

9,not to touch

10,Is-listening

11,Are-winning

12,am not staying

13,isn't working

14,isn't reading

15,isn't raining

16,am not listening

17,Are-making

18,Are-doing

19,Is-sitting

20,is-doing

21,do-putting

22,do-wear

23,is-studying

a. f(\(\dfrac{-1}{2}\)) = \(4.\left(\dfrac{-1}{2}\right)^2+3.\left(\dfrac{-1}{2}\right)-2\) 

               = \(4.\dfrac{1}{4}-\left(\dfrac{-3}{2}\right)-\dfrac{4}{2}\)

               = \(\dfrac{2}{2}+\dfrac{3}{2}-\dfrac{4}{2}\)

               = \(\dfrac{1}{2}\)

Đề sai rồi vì `P>0AAx>=0,x ne 1/2` mà phải tìm để `P<=0` nên nhất thiết mẫu là `2sqrtx-1` mặt khác còn lý do nữa là `x ne 1/2` mà không phải là `1/4` nên mình vẫn băn khoăn nhưng lý do đầu có vẻ thuyết phục hơn và sửa lại là `x ne 1/4` nhé!

`|P|>=P`

Mà `|P|>=0`

`=>P<=0`

`<=>(sqrtx+2)/(2sqrtx-1)<=0`

Mà `sqrtx+2>=2>0AAx>=0`

`<=>2sqrtx-1<0`

`<=>2sqrtx<1`

`<=>sqrtx<1/2`

`<=>x<1/4`

Vậy với `0<=x<1/4` thì `|P|>=P.`

e: \(E=\dfrac{x^2-9-x^2+4-x^2+9}{\left(x+3\right)\left(x-2\right)}\)

\(=\dfrac{x+2}{x+3}\)

a: \(A=\dfrac{4x^2+x^2-2x+1+x^2+2x+1}{\left(x-1\right)\left(x+1\right)}\)

\(=\dfrac{6x^2+2}{\left(x-1\right)\left(x+1\right)}\)

\(A=\dfrac{-4x^2+x^2-2x+1-x^2-2x-1}{\left(1-x\right)\left(1+x\right)}=\dfrac{-4x\left(x+1\right)}{\left(1-x\right)\left(1+x\right)}=\dfrac{4x}{x-1}\\ C=\dfrac{-x^2-4x-4+x^2-4x+4-4x^2}{\left(x-2\right)\left(x+2\right)}=\dfrac{-4x\left(x+2\right)}{\left(x-2\right)\left(x+2\right)}=\dfrac{4x}{2-x}\\ E=\dfrac{x^2-9-x^2+4x-4-x^2+9}{\left(x-2\right)\left(x+3\right)}=\dfrac{-\left(x-2\right)^2}{\left(x-2\right)\left(x+3\right)}=\dfrac{2-x}{x+3}\)

5:

a: Chiều rộng là 18*1/6=3m

S=18*3=54m²

Số viên gạch cần mua là:

54*10^4:30^2=600 viên

b: Số viên gạch phải giảm đi là:

600*5/6=500 viên

a, Thay tọa độ điểm ( 2;5 ) vào hàm số ta được ;

\(2\left(2m-1\right)+m-3=5\)

\(\Rightarrow m=2\)

b, - Gọi điểm cố định hàm số đi qua là M (x0; y0 ) ta được :

\(\left(2m-1\right)x_0+m-3=y_0\)

\(\Leftrightarrow2mx_0-x_0+m-3-y_0=0\)

\(\Leftrightarrow m\left(2x_0+1\right)-x_0-y_0-3=0\)

- Để hàm số luôn đi qua điểm cố định \(\Leftrightarrow\left\{{}\begin{matrix}2x_0+1=0\\x_0+y_0+3=0\end{matrix}\right.\)

\(\Rightarrow\left\{{}\begin{matrix}x=-\dfrac{1}{2}\\y=-\dfrac{5}{2}\end{matrix}\right.\)

Vậy điểm cố định mà hàm số đi qua là : M ( -1/2; -5/2 )

c, - Thay điểm có hoành độ là \(\sqrt{2}-1\) vào hàm số ta được :

\(\left(\sqrt{2}-1\right)\left(2m-1\right)+m-3=0\)

\(\Leftrightarrow m=\dfrac{6+5\sqrt{2}}{7}\)

Vậy ...

Bài 1 mình chỉ viết cái cần điền thôi nha

1 such a beautiful girl

2 so hot that

3 surprised that

4 a heavy box

5 so naughty 

6 such an important language

7 so young 

8 such poor people

9 so well

10 so much

12 so many

Bài 2

1 such 

2 so

3 so

4 such

5 such

6 so

7 such

8 so

3

1 This detective story is so good that I can't put it down

It is such a good detective story that I can't put it down

2 The waiters were so rude that we complained to the manager about them

They are such rude waiters that we complained to the manager about them

3 The lifts were so old that they didn't work

They were such old lifts that they didn't work

4 The food was so awful that we were ill for 3 days

It was such awful food that we were ill for 3 days

Bài 4

1 enough

2 too

3 too

4 enough

5 enough

6 too

7 enough

8 enough

Bài 5

1 The film was so sad that everyone cried

2 He speaks too fast for me to unterstand

3 Have we got enough money to pay for the tickets

4 It was such a good meal that we ate far too much

5 The teacher was stupid enough to believed the children

6 They were such cheap trousers that I bought six pairs

7 Is there enough food for us to feed everyone?

8 The film was so bad that most people walked out

9 He is too old to walk far

10 My boss was kind enough to pay for the meal