???

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

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

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

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

b) Thay \(x=4-2\sqrt{3}\) vào S, ta được:

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

\(=\dfrac{1-\left(4\sqrt{3}-4-6+2\sqrt{3}\right)}{4-2\sqrt{3}}\)

\(=\dfrac{1-2\sqrt{3}+10}{4-2\sqrt{3}}=\dfrac{9-2\sqrt{3}}{4-2\sqrt{3}}\)

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

\(=\dfrac{36+18\sqrt{3}-8\sqrt{3}-12}{4}\)

\(=\dfrac{24+10\sqrt{3}}{4}=\dfrac{12+5\sqrt{3}}{2}\)

a)\(S=\left(\dfrac{x+1+\sqrt{x}}{x+1}\right):\left(\dfrac{x+1-2\sqrt{x}}{\left(\sqrt{x}-1\right)\left(x+1\right)}\right)\) \(đk:x\ne\pm1\)

\(S=\dfrac{x+1+\sqrt{x}}{x+1}.\dfrac{\left(\sqrt{x}-1\right)\left(x+1\right)}{\left(\sqrt{x}-1\right)^2}\)

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

b)\(x=4-2\sqrt{3}=\left(\sqrt{3}-1\right)^2\left(TMĐK\right)\)

\(\sqrt{x}=\sqrt{3}-1\)

Từ đó ta có :

\(S=\dfrac{4-2\sqrt{3}+1+\sqrt{3}-1}{\sqrt{3}-1-1}\)

\(S=-5-2\sqrt{3}\)

my parents are enjoying their summer vacation in Miami

they are drinking coffee with friends

Look! it's starting to rain!

They are buying some cakes for the kids at home

What is your brother doing?

1. What did the people do when you were there

2. I visited Dalat with my parents.

3. What do you think of Tam?

4. The life in countryside is peaceful and more than I expected

1.What did the people do when you were there?

2.I visited Da Lat with my parents.

3.What do you think of Tam?

4.The life in the countryside is more peaceful than I expected.