5x² - 4(x² - 2x + 1) - 5 = 0

=> 5x² - 4x² + 8x - 4 - 5 = 0 

=> x² + 8x - 9 = 0

=> x² + 9x - x - 9 = 0 

=> x(x + 9) - (x + 9) = 0

=> (x + 9)(x - 1) = 0

=> x + 9 = 0 => x = -9

hoặc x - 1 = 0 = > x = 1

                                                                       Vậy x = -9, x = 1

\(5x^2-4\left(x^2-2x+1\right)-5=0\)

\(\left(5x^2-5\right)-4\left(x^2-2.1.x+1^2\right)=0\)

\(5\left(x^2-1\right)-4\left(x-1\right)^2=0\)

\(5\left(x-1\right)\left(x+1\right)-4\left(x-1\right)\left(x-1\right)=0\)

\(\left[5\left(x+1\right)-4\left(x-1\right)\right]\left(x-1\right)=0\)

\(\left(5x+5-4x+4\right)\left(x-1\right)=0\)

\(\left(x+9\right)\left(x-1\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x+9=0\\x-1=0\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x=-9\\x=1\end{cases}}\)

Vậy \(\orbr{\begin{cases}x=-9\\x=1\end{cases}}.\)

1. How far is it from your house to the school?

It is about 200 metres.

2. How far is it from your house to the zoo?

It is about 3 km.

3. How far is it from your house to the supermarket?

It is about 400 metres.

4. How far is it from your house to the bus station?

It is about 100 metres.

5. How far is it from your house to the playground?

It is about 2 km.

kiểm tra kết quả kiểu gì trong khi mới làm dc nửa câu 1:)?

1. How far is it from your house to the school?

It is about 100  metres.

2. How far is it from your house to the zoo?

It is about 5  km.

3. How far is it from your house to the supermarket?

It is about 400  metres.

4. How far is it from your house to the bus station?

It is about 356  metres.

5. How far is it from your house to the playground?

It is about 3 km.

-Chị gái tôi đánh phấn rất xinh.

- Tôi đánh một giấc ngủ tới sáng .

Mình đánh hơi lỗi xíu, yhoong cảm nha, cái giúo là giúp đó. Các bạn có đ/á nhanh thì mình k nha

yhoong cảm là thông cảm nha, hihi, mình xin lỗi vì mình đang gấp 

D

Câu 6: A

Câu 7: C

Câu 8: B

Câu 9: C

Câu 10: C