1) Vì x=25 thỏa mãn ĐKXĐ nên Thay x=25 vào biểu thức \(A=\dfrac{\sqrt{x}-2}{x+1}\), ta được:

\(A=\dfrac{\sqrt{25}-2}{25+1}=\dfrac{5-2}{25+1}=\dfrac{3}{26}\)

Vậy: Khi x=25 thì \(A=\dfrac{3}{26}\)

2) Ta có: \(B=\dfrac{\sqrt{x}-3}{\sqrt{x}+1}+\dfrac{2x+8\sqrt{x}-6}{x-\sqrt{x}-2}\)

\(=\dfrac{\left(\sqrt{x}-3\right)\left(\sqrt{x}-2\right)}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+1\right)}+\dfrac{2x+8\sqrt{x}-6}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+1\right)}\)

\(=\dfrac{x-5\sqrt{x}+6+2x+8\sqrt{x}-6}{\left(\sqrt{x}-2\right)\left(\sqrt{x}+1\right)}\)

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

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

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

câu 3 chứ

<=>55 - 3x = 25

<=>-3x = 25 - 55
<=>-3x = -30
<=>x=10

55 - 3x = (-5)²

55 - 3x = 25

3x = 55 - 25

3x = 30

x = 30 : 3

x = 10

Vậy x = 10

55 - 3x = (-5)²

55 - 3x = 25

3x = 55 - 25

3x = 30

x = 30 : 3

x = 10

3 careless

4 bleed

V

1 Hung has colllected stamps since 2000

2 The front yard isn't large enough to play soccer in

3 Milk is delivered twice a week by the milkman

4 When did you bought this computer?

5 His car doesn't run as fasst as a race car

6 Two languages can be spoken well by Lan

VI

1 T

2 F

3 T

4 T

VII

1 Mr. Nam is arriving in Hue tonight

2 They are going back to Englang in two months

3 It is not difficult to tránlate this sentence into English

4 Would you mind lending me your dictionary?

3 careless

4 bleed

V

1 Hung has colllected stamps since 2000

2 The front yard isn't large enough to play soccer in

3 Milk is delivered twice a week by the milkman

4 When did you bought this computer?

5 His car doesn't run as fasst as a race car

6 Two languages can be spoken well by Lan

VI

1 T

2 F

3 T

4 T

VII

1 Mr. Nam is arriving in Hue tonight

2 They are going back to Englang in two months

3 It is not difficult to tránlate this sentence into English

4 Would you mind lending me your dictionary?

Kiểm định chất lượng học sinh giỏi??

đề ôn thì bn tự làm đi, nó giúp bn ôn chứ ko phải tụi mk ôn hộ bn

Bạn tự làm đi, đề ktra của bạn mà. Nhỡ đâu bạn làm đc thì sao, cũng phải nhờ vào cái não tính toán 1 tí chứ

Đăng tách ra

Dài

Quá /////////////???????//////

cho xin cái đề bài y

đề bài đâu em