a: \(P=\dfrac{2x+4\sqrt{x}-x-6\sqrt{x}}{x-4}=\dfrac{x-2\sqrt{x}}{x-4}=\dfrac{\sqrt{x}}{\sqrt{x}+2}\)

b: Thay x=1 vào P, ta được:

\(P=\dfrac{1}{1+2}=\dfrac{1}{3}\)

\(B=10+5\sqrt{3}+10-5\sqrt{3}=20\)

a: \(=\sqrt{2}-1\)

b: \(=\sqrt{3}+1+2-\sqrt{3}=3\)

Đk: \(x\ge4\)

\(A=\sqrt{x+4\sqrt{x-4}}+\sqrt{x-4\sqrt{x-4}}\)

\(=\sqrt{\left(x-4\right)+4\sqrt{x-4}+4}+\sqrt{\left(x-4\right)-4\sqrt{x-4}+4}\)

\(=\sqrt{\left(\sqrt{x-4}+2\right)^2}+\sqrt{\left(\sqrt{x-4}-2\right)^2}\)

\(=\sqrt{x-4}+2+\left|\sqrt{x-4}-2\right|\)

TH1:\(\sqrt{x-4}>2\Leftrightarrow x>8\)

\(A=\sqrt{x-4}+2+\sqrt{x-4}-2=2\sqrt{x-4}\)

TH2:\(\sqrt{x-4}\le2\Leftrightarrow4\le x\le8\)

\(A=\sqrt{x-4}+2-\left(\sqrt{x-4}-2\right)=4\)

Vậy...

1. What about playing volleyball?

What about playing volleyball?

2. The document is translated into English.

1A

2C

3D

4ko có đáp án đúng

Câu 17: B

Câu 19: C

Câu 18: C

1.been learning

2.having

3.inviting

4.to keep

5.turning

6.and

1....learned
2....having
3....inviting..
4....to keep.
5....turning
6....which
2. 
1. They don't go for a walk because it is raining heavily.