Không những nó học giỏi toán mà nó còn học giỏi tiếng việt.

-> Cặp từ chỉ quan hệ tăng tiến

 x² + x - 2 = 0

⇔ x²+2x-x-2=0

⇔ x.(x+2) - (x+2)=0

⇔ (x-1)(x+2)=0

⇔\(\left[{}\begin{matrix}x-1=0\\x+2=0\end{matrix}\right.\)

⇔\(\left[{}\begin{matrix}x=1\\x=-2\end{matrix}\right.\)

\(A=\left(\dfrac{9-3x}{x^2+4x-5}-\dfrac{x+5}{1-x}-\dfrac{x+1}{x+5}\right):\dfrac{7x-14}{x^3-1}\)

a. Tìm x để A<0

b. Tìm x ∈ Z để A ∈ Z

c. Tìm GTLN của M=\(\dfrac{2}{x-2}:A\)

He asked me, "Do you understand all the rules?"

-> He asked me if I understood all the rules

Does your sister (wash) _wash___the disher everyday?
They (not have) don't have breakfast every morning 

1. It/compulsory/ wear / safety/ helmet / a motorbike

⇒ It is compulsory to wear a safety helmet on a motorbike.

2/ That block / flats/ pull down/ now/ because /it/ unsafe

⇒ That block flat is being pulled down now because it is unsafe.

was cooking → cooked

1+1=2

1. I sent my friend a letter in London last week.

--> A letter was sent my friend in London last week by me.

2. I last saw him when I was a student.

--> I haven’t seen him since i was a student.