Make up questions

Vd:I am 13 years old?He is a doctor

How old a you?What does he do?

1.My school has 21 classer.

2.They sometimes go saoling in the fall.

3.The police station is opposite the drugstore.

4.She speaks French.

5,They often have lunch at 11o'clock.

6.She watches T.V every evening.

7.We have English on Monday ang Thursday.

8.The Great Wall of China is the longest structure in the world

Mik cần gấp lắm. Cảm ơn nha

5x² - 10xy + 5y² - 20z²

= 5.(x² - 2xy + y² - 4z²)

= 5.[(x² - 2xy + y²) - (2z)²]

= 5.[(x - y)² - (2z)²]

= 5.(x - y - 2z).(x - y + 2z)

x².(1 - x²) - 4 + 4x²

= x².(1 - x²) - 4.(1 - x²)

= (1 - x²).(x² - 4)

= (1 - x)(1 + x)(x - 2)(x + 2)