⇒ Do giai cấp vô sản lãnh đạo.

a) \(x^2 (x+1)-2x(x+1)+x+1 \\ =(x+1)(x^2-2x+1)\\=(x+1)(x-1)^2\)

b) \(4x^2 -8x+3 \\= (2x^2)-2.2x .2 + 2^2 -1 \\=(2x-2)^2-1^2\\=(2x-2+1)(2x-2-1)\\= (2x-1)(2x-3)\)

\( (x-3)^2-(x+3)^2=0 \\ (x-3+x+3)(x-3-x-3)=0 \\ 2x.(-6)=0 \\ x=0 \)

\((2x+y)^2+\dfrac{1}{3}-\dfrac{4x+5}{6y+7}\) → sqr(2*x+y)+1/3-(4*x+5)/(6*y+7)

1. Where are you talking this semester ?

2. How long is she staying there ?

3. What is she worried about ?  

4. When did you begin to study English ?

5. Where do they live ?

6. Where did you go last night ?

7. Why do you like ''Tom and Jerry" ?

- Đề sai ?

\((3x+5)(2x+11)-(2x+3)(3x+7)\\=6x^2+33x+10x+55-(6x^2+14x+9x+21)\\=6x^2+43x+55-6x^2-23x-21\\=20x+34\)

\((3x+5)(2x+11)-(2x+3)(3x+7)\\=6x^2+33x+10x+55-(6x^2+14x+9x+21)\\=6x^2+43x+55-6x^2-23x-21\\=20x+34\)

Vậy biểu thức phụ thuộc vào giá trị của x.

⇒ Hồ Chí Minh.