chứng minh các đa thức sau

a) \(\dfrac{a^3-4a^3-a+4}{a^3-7a^2+14a-8}\)= \(\dfrac{a+1}{a-2}\)

b)\(\dfrac{x^4+x^3+x+1}{x^4-x^3+2x^2-x+1}=\dfrac{\left(x+1\right)^2}{x^2+1}\)

Rút gọn các phân thức sau :

a) \(\dfrac{\left(a+b\right)^2-c}{a+b+c}\)

b) \(\dfrac{a^2+b^2-c^2+2ab}{a^2-b^2+c^2+2ac}\)

c)\(\dfrac{2x^2-7x^2-12x+45}{3x^3-19x^3+33x-9}\)

Make question and answers using the suggested words .

1. Which / your parents / can speak / Tay language ? - My father can.

2. How / it / from / here / the communal house ? - It / 3km / from / here / there .

3. What / most ethnic people / Viet Nam / live on ? - They / live / rice farming.

4. Cham / population / about 162 thousand inhabitants / live / provices / Ninh Thuan , Binh Thuan , Dong Nai and Tay Ninh.

Viết câu giữ nguyên nghĩa

No cities VN have a larger population than HCM city.

➜ HCM city have ____________

Mai is a faster swimmer than me .

➜ Mai swims______________

Living in the countryside is more convenient than living in the countryside.

➜ living in the countryside is not ____________