Rút gọn
a) \(\sqrt{5}.\sqrt{45}-\sqrt{13}.\sqrt{52}\)
b) \(\sqrt{2300}.\sqrt{23}+\frac{\sqrt{6}}{\sqrt{150}}+\sqrt{\frac{25}{144}}\)
c) \(\sqrt{9-4\sqrt{5}}-\sqrt{9+4\sqrt{5}}\)
d) \(\sqrt{4-\sqrt{7}}-\sqrt{4+\sqrt{7}}\)
e) \(\left(4+\sqrt{5}\right)\left(\sqrt{10}-\sqrt{6}\right)\left(\sqrt{4-\sqrt{15}}\right)\)
Bài 2: Giải các phương trình sau:
a \(\frac{3x+2}{2}-\frac{3x+1}{6}=\frac{5}{3}+2x\)
b \(\left(x+1\right)\left(x+2\right)=\left(2-x\right)\left(x+2\right)\)
c \(\frac{x+5}{x-5}-\frac{x-5}{x+5}=\frac{20}{x^2-25}\)
d\(x^2+6x+9=114\)
2 Tìm giá trị nhỏ nhất của biểu thức :
a) A=2x^2-8x+10 ; b) B= x(x+1)(x^2+x-4)
d) D=9x^2-6x+5 ; e) E=x^2+3-1
f) F=(x^2+5x+4)(x+2)(x+3) ; G= (x-3)(x-4)(x^2-7x+8)
h) H=\(\left|x-7\right|+\left|x+5\right|\) ; i) I=\((2x-1)^2-3\left|2x-1\right|+2\)
k) K=\(\left|x^2+x+1\right|+\left|x^2+x-12\right|\)
Phân tích đa thức thành nhân tử = phương pháp đổi biến:
a) \(\left(x^2+x\right)-2\left(x^2+x\right)-15\)
b) \(x^2+2xy+y^2-x-y-12\)
c) \(\left(x^2+x+1\right)\left(x^2+x+2\right)-12\)
d) \(\left(x+2\right)\left(x+3\right)\left(x+4\right)\left(x+5\right)-24\)
e) \(\left(4x+1\right)\left(12x-1\right)\left(3x+2\right)\left(x+1\right)-4\)
Phân tích các đa thức sau thành nhân tử:
a) \(4x^4-32x^2+1\)
b) \(x^6+27\)
c) \(\left(2x^2-4\right)^2+9\)
d) \(4x^4+1\)
e) \(4x^4+y^4\)
f) \(x^4+324\)
Tìm tất cả các số nguyên n để:
a) \(\left(2n^2+n-7\right)\) ⋮\(\left(n-2\right)\)
b) \(\left(10n^2+n-10\right)\) ⋮\(\left(n-1\right)\)
c) \(\left(3n^3+10n^2-5\right)\) ⋮\(\left(3n+1\right)\)
d) \(\left(n^3-3n^2-3n-1\right)\)⋮\(\left(n^2+n+1\right)\)
Đánh dấu trọng âm
1. artistic 6. physical
2. athletic 7. heroic
3. historic 8.poetic
4.historical 9. botanic
5.logical 10. botanical
1. cantonese 2. taiwanese
3. japanese 4. Portuguese
5.employee 6. adoptee
7.addressee 8. interviewee
1. sociology 2. zoology
3. bibliography 4. climatology
5. astrology 6. demography
1. competitive 2. ifnitive
3. repetitive 4. positive
5. ability 6.possibility
7. curiosity 8.nationality
ZComplete the blank with appropriate nouns. Verbs Nouns 1. concentrate 2. compose 3. consider . 4. construct 5. coordinate 6. depress 7. donate 8. erect 9. found 10. locate 11. apply
12. generate 13. oblige
Read the following passage and choose the correct answer to each of the questions that follow.
Write your answer (A, B, C, or D) in the space given on the right.
There was a nasty (1) at Newton crossroads yesterday morning. A. bus overturned, and some of the passengers
were badly (2). Several (3) helped to pull the people out of the (4) and give them (5) until help arrived. Soon the
injured were taken to the nearest hospital by ambulance, but there were so many that the (6) department there
had difficulty in treating them all. Most of the passengers were found to be suffering from severe (7). The bus had
crashed into a brand new car and had completely (8) it, although fortunately there was no one in the car.
Moreover, the new car was fully (9). The police took the names and addresses of as many (10) as possible. It is
believed that the injured passengers have the right to claim compensation.
1. A. event B. accident C. happening D. emergency
2. A. pained B. wounded C. knocked down D. injured
3. A. bystanders B. spectators C. audience D. supporters
4. A. wreckage B. crash C. damage D. accident
5. A. medicine B. cures C. remedy D. first aid
6. A. injury B. ambulance C. casualty D. operating
7. A. surprise B. shock C. worry D. nervousness
8. A. damaged B. knocked C. wrecked D. crashed
9. A. insured B. guaranteed C. protected D. purchased
10. A. suspects B. witnesses C. viewers D. judges