Vào mùa đông, khí hậu khá lạnh, cơ thể ta thường run cầm cập và đôi khi sẽ nổi da gà. Em hãy giải thích hiện tượng trên thể hiện vai trò gì của da? Ngoài ra, da còn có chức năng nào khác nữa?

a) \(x\left(x+4\right)-4x+1=0\)

b) \(2\left(x-3\right)+4=2x+2\)

c) \(\dfrac{x+3}{2}-\dfrac{2x+1}{4}=\dfrac{1}{4}\)

d) \(\dfrac{x^2+3x}{x+3}+3=0\)

e) \(x^2-3x\left(x-1\right)-3x-2=0\)

Sửa lỗi sai:

1. Job for young people is becoming more hardly to find.

2. Tom's bag is order than mine, but Jane's is the most older.

3. Online shopping is much convenient than shopping in a shop.

4. The weather is getting colder and more colder.

5. The house is more expensive to the apartment.

6. We speak English fluent now than last year.

7. The cost of living in the contryside is more low than in the city.

8. Dog are much more better than human beings at detecting smells.

9. A camel runs much more slowly as a horse.

10. For many ethnic groups in the mountains, the horse is still the more convenient means of transport.

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

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