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

B = \(\dfrac{y-5\sqrt{x}}{x-16}\) - \(\dfrac{2}{4-\sqrt{x}}\) + \(\dfrac{3}{\sqrt{x}+4}\)

Bài 1: Rút gọn :            

a) \(\sqrt{16ab^2}\) : \(\sqrt{4a}\) với a > 0 , b < 0

b) \(\sqrt{52a^3}\) : \(\sqrt{13a}\) với a > 0

c) \(\dfrac{2\sqrt{a^2\left(1-a\right)^2}}{\sqrt{50}}\) với a > 1

d) \(\dfrac{\sqrt{3ab^4}}{\sqrt{27a}}\) với a > 0

e) \(\dfrac{\sqrt{125a}}{\sqrt{5a}}\) với a > 0 

f) \(\dfrac{\sqrt{48x^3}}{\sqrt{3x^5}}\) với x > 0

Bài 1: Tính:

a) \(\left(\sqrt{\dfrac{1}{7}}-\sqrt{\dfrac{16}{7}}+\sqrt{7}\right)\) : \(\sqrt{7}\)

b) \(\sqrt{36+12\sqrt{15}}\) : \(\sqrt{6}\)

c) \(\left(\sqrt{\dfrac{1}{3}-\sqrt{\dfrac{4}{3}}+\sqrt{3}}\right)\) : \(\sqrt{3}\)

Bài 2: Tính:

a) A=\(\left(\sqrt{27}-\sqrt{12}+2\sqrt{6}\right)\) : \(3\sqrt{3}\)

b) B=\(\left(\sqrt{12}-2\sqrt{18}\right)\) . \(\dfrac{\sqrt{2}}{2}\)

c) C=\(\left(\dfrac{1-\sqrt{2}}{1+\sqrt{2}}.\dfrac{1+\sqrt{2}}{1-\sqrt{2}}\right)\) : \(\sqrt{72}\)

Bài 1:Tính giá trị biểu thức sau:

a) A=\(\sqrt{\left(2-\sqrt{5}\right)^2}\) + \(\sqrt{\left(2\sqrt{2}-\sqrt{5}\right)^2}\)

b) B=\(\sqrt{\left(\sqrt{7}-2\sqrt{2}\right)^2}\) + \(\sqrt{\left(3-2\sqrt{2}\right)^2}\)

c) C=\(\sqrt{11+6\sqrt{2}}\) - \(\sqrt{11-6\sqrt{2}}\)

Bài 2: Rút gọn biểu thức:

a) B= 3\(\sqrt{9a^6}\) - \(6a^3\)

b) C=\(\sqrt{a^2+6a+9}\) + \(\sqrt{a^2-6a+9}\) (-3\(\le\)a\(\le\)3)

Bài 1: Cho biểu thức A=\(\dfrac{x-2}{x+2}\) - \(\dfrac{x}{x-2}\) - \(\dfrac{9x+2}{4+x^2}\). Với x\(\ne\)\(\pm\)2.

a. Chứng minh A=\(\dfrac{3}{x-2}\).

b. Tính giá trị của A khi 3x(2x+1) - 6(2x+1)=0.

c. Tìm giá trị nguyên của x để A nhận giả trị nguyên.

Bài 2: Cho biểu thức A=\(\dfrac{x}{x-2}\) + \(\dfrac{2-x}{x+2}\) + \(\dfrac{12-10x}{x^2-4}\). Với x\(\ne\)\(\pm\)2.

a. Rút gọn biểu thức A.

b. Tìm giá trị nguyên của x để A nhận giá trị nguyên.

Cho biểu thức A=\(\dfrac{3+x}{3-x}\) - \(\dfrac{4x^2}{x^2-9}\) - \(\dfrac{3-x}{3+x}\). Với x khác \(\pm\)3

a. Rút gọn biểu thức A.

b. Tìm x để A=-3.

c. Tính giá trị của A khi x=3.

Cho biểu thức M=\(\dfrac{x^2+2x+1}{x^2-1}\). Tìm giá trị của x để M=2

Pask 1: Mark the letter A, B, C or D on your answer than needs correction the following questions.

1. You should to read(A) more books if(B) you want to improve(C) your English vocabularry(D).

2. We cancelled(A) our camping(B) trip because of(C) it rained heavily(D).

3. His family was very(A) poor, because(B) he had to work(C) for a(D) company.

Pask 1: Read the passage and mark A, B, C or D on your answer the correct answer yo complete the passage.

      My name's Mandi. Three months ago, I went to disco where I met a boy called Tom. I guessed he was older than me, but I liked him and thought it didn't matter. We danced a couple of times, then we chatted. He said he was 18, then asked how old I was. I told him I was 16. I thought that if I told him my real age, he wouldn't want to know me, as I'm only 13. After the dicso we arranged to meet the following weekend. The next Saturday we went for a hamburger and had a real laugh. Afterwards he walked me to my street and kissed me goodnight. Things went really well. We see each other a couple of times a week, but I've had to lie to my parents about where I'm going and who with. I've always got on with them, but I know if they found out how Tom was, they'd stop me seeing him. Now I really don't know what to do. I can't go on lying to my parents every time I go out, and Tom keeps asking he can't come around to my house. I'm really worried and I felt complicated. I need some advice now.                              " From the helpline on the magazine for teens."

1. What's the best title for the passage ?

A. Mandi's parents are angry with her.

B. Mandi's love with a naughty boy makes her parents bored.

C. Tom has been behaving strangely.

D. The worries about Mandi's dishonesty.

2. Why has Mandi written this ?

A. to describe her boyfriend                    B. to explain a problem

C. to defend her actions                 D. to prove how clever she is 

3. Who is she writing to ? 

A. her parents    B. a teenage magazine   C. her boyfriend   D. a school friend   

4. Why can't Tom come to Mandi's house ?

A. He's nervous of meeting her parents.

B. She doen't want her parents to meet him.

C. She doén't want him to see where she lives.

D. Her parents don't like him.

5. According to the passage, all the followings are true, but one is NOT TRUE.

A. Tom doesn't know how old Mandi is.

B. Everyone doesn't know that she is telling lie.

C. Mandi should start by being honest with everyone.

D. Mandi tries to follow Tom so that he will love her.

Bài 1: Rút gọn biểu thức:

a) 2x(3x-5)-6x²       b) (x+3)(1-x)+(x-2)(x+2)        c) (3x+1)²-(1+3x)(6x-2)+(3x-1)²

Bài 2: Phân tích đa thức thành nhân tử:

a) 9x²-1       b) 2(x-1)+x²-x        c) 3x²+14x-5

Bài 3: Tìm x biết:

a) 2x(x-1)-2x²=4          b) x(x-3)-(x+2)(x-1)=5        c) 4x²-25+(2x+5)²=0

Bài 4: Cho tam giác ABC , có D là trung điểm đoạn thẳng BC , E là trung điểm của AB lấy điểm F đối xứng với điểm D qua E .

a) Chứng minh tứ giác FADB là hình bình hành.

b) Kẻ FG vuông với AB ;  DH vuông với AB ; (G;HϵAB). Chứng minh FD=AC;\(\widehat{BFH}\)=\(\widehat{ADG}\).

c) Vẽ điểm Q đối xứng với điểm C qua A , DQ cắt đoạn AB tại điểm I , M là trung điểm AD.

Chứng minh F , M , I thẳng hàng