1. Chứng minh |x-y|<|1-xy| với |x|<1,|y|<1
2. a) Tìm GTNN của biểu thức A=x^2-2x+1975/x^2
b) Cho x,y>0, x+y=1. Chứng minh: 2(x^4+y^4)+1/2xy>=2.1/4
1. Phân thích đa thức thành nhân tử
a) \(x^3-2x^2-6x+12\)
b) \(x^4-7x^2+12\)
c) \(x^2-5x+4\)
d) \(3x^2+5x+2\)
e) \(x^3-x+3x^2y+3xy^2+y^3-y\)
Tìm số tự nhiên n để phép chia sau đều là phép chia hết
a)15xn+2ynn : x3y4
b)(-1/2x2ny77) : 3/10xn+3y2
c)18xn+2 : -6x5
d)2xny33: 5x2yn-1
Rút gọn phân thức \(\dfrac{20x(2-x)}{12x(x-2)^2}\)
Nếu (x – y)/(z – y) = -10 (y ≠z) thì giá trị của biểu thức (x – z)/(y – z) là ...
Phân tích tha hf nhân tử :
a) a^2 ( x - y ) + y - x .
b) m^2 - 25y^2 + 10y - 1
c) a^2 - 4x^2 + 8x -4
ĐỊNH Lí TA LÉT ĐẢO NHA MN
Giải phương trình
a)\(\frac{x+5}{x^2-5x}-\frac{x-5}{2x^2+10x}=\frac{x+25}{2x^2-50}\)
b) \(\frac{7}{8x}+\frac{5-x}{4x^2-8x}=\frac{x-1}{2x\left(x-2\right)}+\frac{1}{8x-16}\)
Bài 6. Complete the sentences with right prepositions:
1. That’s very kind ____ you to help me _____ this Math.
2. We hope to earn some money _____our school Y & Y.
3. What did you do _____ the ninth of April, 2002? (April 9th , 2002)
4. Well, let’s go ____ a walk ______ the weekend.
5. Minh has high marks ___ exam ___working very hard.
6. Are you interested _____ studying English?
7. When did you see him? _____ lunch today.
8. Does it rain _____ spring?
9. His birthday is ____ May 1st .
10. I am different ______ my sister.
11. I don’t know he is doing ___ the moment
12. She was interested ____ folktales.
13. I’ll be home ______ 7.00 because I want to see the seven o’clock news.
14. I go to school _____ Monday ______ Saturday.
15. We’ve not seen her _______ 2006.