1 My sister has learned English for 5 years

2 A supermarket was built near the airport last year

3 I spent three hours cleaning the house yesterday

6 The wall built three weeks ago fell down

7 Unless you leave me alone, I will call the police

8 The suspects are being followed by the police 

10 Nobody in this team is as good at playing football as Tom

ok

1.What

2.a

3.How are you?

4.Are

5.there

6.what is that

...

bài này của lớp 6?

1 b

2 c

3 b

4 b

5 a

Bài 11:

a: Ta có: \(P=\dfrac{x^2-\sqrt{x}}{x+\sqrt{x}+1}\)

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

\(=x-\sqrt{x}\)

b: Để P=2 thì \(x-\sqrt{x}-2=0\)

hay x=4

Bài 10:

a: Ta có: \(A=\left(1+\dfrac{\sqrt{x}}{x+1}\right):\left(\dfrac{1}{\sqrt{x}-1}-\dfrac{2\sqrt{x}}{x\sqrt{x}+\sqrt{x}-x-1}\right)\)

\(=\dfrac{x+\sqrt{x}+1}{x+1}:\dfrac{x-2\sqrt{x}+1}{\left(x+1\right)\left(\sqrt{x}-1\right)}\)

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

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

b: Để A<0 thì \(\sqrt{x}-1< 0\)

hay x<1

Kết hợp ĐKXĐ, ta được: \(0\le x< 1\)

Để A=-1 thì \(x+\sqrt{x}+1=-\sqrt{x}+1\)

\(\Leftrightarrow x=0\)

c: Thay x=4 vào A, ta được:

\(A=\dfrac{4+2+1}{2-1}=7\)

Bạn để ý \(\left(2\sqrt{x}-1\right)\left(\sqrt{x}+4\right)=2x+7\sqrt{x}-4\)

Bạn chỉ cần quy đồng lên rồi tính thôi.

9) Ta có: \(\dfrac{\sqrt{x}+2}{x-5\sqrt{x}+6}-\dfrac{\sqrt{x}+3}{2-\sqrt{x}}-\dfrac{\sqrt{x}+2}{\sqrt{x}-3}\)

\(=\dfrac{\sqrt{x}+2+x-9-x+4}{\left(\sqrt{x}-2\right)\left(\sqrt{x}-3\right)}\)

\(=\dfrac{\sqrt{x}-3}{\left(\sqrt{x}-2\right)\left(\sqrt{x}-3\right)}\)

\(=\dfrac{1}{\sqrt{x}-2}\)

Ta có: \(M_{X_2O_5}=M_{Ag}=108\left(đvC\right)\) \(\Rightarrow M_X=\dfrac{108-16\cdot5}{2}=14\left(đvC\right)\)

  Vậy X là Nitơ (N)

          Công thức của hợp chất là N₂O₅

Khẳng định:

1.     I visited a new art exhibition last weekend.

2.     She completed her assignment before the deadline.

3.     They attended the concert and had a great time.

4.     We explored the ancient ruins during our vacation.

5.     He read a fascinating book about space exploration.

6.     The team won the championship last year.

7.     I cooked a delicious dinner for my family yesterday.

8.     She studied diligently for her final exams.

9.     They traveled to Paris and enjoyed the Eiffel Tower view.

10.     We organized a successful charity event in our community.

Phủ định:

1.     I didn't visit the museum as I had planned.

2.     She didn't finish reading the novel due to lack of time.

3.     They didn't participate in the volunteer project due to scheduling conflicts.

4.     We didn't get to see the sunrise during our camping trip.

5.     He didn't learn to play the piano despite his initial enthusiasm.

6.     The team didn't qualify for the playoffs this season.

7.     I didn't have time to bake cookies for the bake sale.

8.     She didn't practice speaking French regularly.

9.     They didn't have a chance to visit the famous art gallery.

10.   We didn't manage to fix the broken car before the road trip.

\(y'=\left(x^3\right)'-\left(4x^2\right)'+\left(1\right)'=3x^2-8x\)

Hệ số góc của tiếp tuyến tại điểm có hoành độ bằng 1 là \(y'\left(1\right)\)

\(y'\left(1\right)=3.1^2-8.1=-5\)