cho tam giác ABC vuông tại A. Gọi E, G, F lần lượt là trung điểm AB, BC, AC

a, Tứ giác AEGF là hình j? Vì sao?

b, EI // BF (I ϵ GF) Chứng minh AG, BI, EF đồng quy.

c, Tìm điều kiện của tam giác ABC để tứ giác AGCI là hình vuông

a, \(x^2+4x+3=0\)

b, \(2x^2-5x+3=0\)

c, x(9x - 5) = 6

d, \(x^4-5x^2+4=0\)

e, \(\left(x+\dfrac{1}{x}\right)^2-3\left(x+\dfrac{1}{x}\right)+2=0\)

f, \(\left(x-1\right)x\left(x+1\right)\left(x+2\right)-24=0\)

g, \(x^4-4x^3+6x^2-4x+1=0\)

tìm x

a, \(x^2+x+\dfrac{1}{4}=\dfrac{9}{4}\)

b, \(25x^2-16\left(x+2\right)^2=0\)

c, \(\left(2x+1\right)^2=\left(x-1\right)^2\)

d, \(9x^2-6x=-1\)

e, \(4x^2-9=0\)

f, \(x^3-9x^2+27x-35=0\)

g, \(x^2-6x-7=0\)

tìm x

a, \(\left(x+2\right)^3-\left(x+1\right)\left(x^2-1+1\right)-6\left(x-1\right)^2=23\)

b, \(\left(x+3\right)\left(x^2+3x+9\right)-x\left(x-2\right)\left(x+2\right)+11=0\)

c, \(x\left(x-3\right)-x+3=0\)

d, \(\left(x-1\right)\left(x+2\right)-2x-4=0\)

e, \(x^3-3x^2-4x+12=0\)

f, \(9\left(x-1\right)-x^3+x^2=0\)

g, \(x^3-2x^2+x-2=0\)

h, \(\left(9-x^2\right)\left(2x+1\right)=0\)

tìm x

a, \(\left(x+2\right)^2-x\left(x+3\right)=2\)

b, \(\left(x+2\right)\left(x-2\right)-\left(x+1\right)^2=7\)

c, \(6x^2-\left(2x+1\right)\left(3x-2\right)=1\)

d, \(\left(x+2\right)\left(x+3\right)-\left(x-2\right)\left(x+1\right)=2\)

e, 6(x-1)(x+1) - (2x-1)(3x+2) + 3 = 0

f, \(x\left(3x+1\right)+\left(x-1\right)^2-\left(2x+1\right)\left(2x-1\right)=0\)

g, \(\left(x+1\right)^3+\left(2-x\right)^3-9\left(x-3\right)\left(x+3\right)=0\)

h, \(\left(x-1\right)^3-\left(x+3\right)\left(x^2-3x+9\right)+3x^2=25\)

phân tích đa thức thành nhân tử

a, \(x^3y+x-y-1\)

b, \(x^2\left(x-2\right)+4\left(2-x\right)\)

c, \(x^3-x^2-20x\)

d, \(\left(x^2+1\right)^2-\left(x+1\right)^2\)

e, \(6x^2-7x+2\)

f, \(x^4+8x^2+12\)

g, \(\left(x^3+x+1\right)\left(x^3+x\right)-2\)

h, \(\left(x+1\right)\left(x+2\right)\left(x+3\right)\left(x+4\right)+1\)

i, \(-\left(x^2+2\right)^2+4x\left(x^2+2\right)-3x^2\)

j, \(81x^4+4y^4\)

Phân tích đa thức thành nhân tử

a, \(x^4y^4+64\)

b, \(x^3+3x^2y+3xy^2+y^3-x-y\) 

c, \(x^8+x+1\)

d, \(x^3+y^3-2\left(x^2-y^2\right)\)

e, \(\left(x^2+y^2\right)-2x^2-2y+1\)

f, \(x^2+5x+6\)

g, \(\left(x^2+x+1\right)\left(x^2+x+2\right)-6\)

phân tích đa thức thành nhân tử

a, \(2xy+5x^2y-x^3y\)

b, \(2\left(x-y\right)+xy-x^2\)

c, \(3x^2+2x-1\)

d, \(-x^2+4x-3\)

e, \(x^2-7x+12\)

f, \(5x\left(x^2-y^2\right)+2y\left(x+y\right)\)

g,\(x^2-\dfrac{3}{2}x-1\)

h, \(3x+3y-x^2-2xy-y^2\)

Vt lại câu cho nghĩa k thay đổi

1. There's a tradition that English people drink a lot of tea (follow)

2. Last year, we went to Thailand on Tet holiday (broke)

3. The Vietnamese have the custom of worshipping ancestors (there)

4. It's the custom for Vietnamese parents to celebrate their baby's first month (have)

5. According to tradition, Vietnamese people celebrate the Mid - Autumn Festival every day (There)

6. The Ok Om Bok Festival takes place in Octorber (organize)

7. It's a good idea to hand bowls with both hands (should)

8. We should wait for the host to start eating (better)

9. Never use bad words in conversations with others, especially wih older people (had)