B

Bài 1: a) x(x-y)+2(x-y)

           = (x-y)(x+2)

b) x²-4y²= (x-2y)(x+2y)

Bài 2: 5(x-3)+x²-3x=0

        5(x-3)+ x(x-3)=0

       (x-3)(5+x)=0

x-3=0 hay 5+x=0

x=3 hay x=-5

Nhiu đó th đó bn

1. My sister is often goes to the cinema with her friends on Fridays

2. That dog is not as dangerous as it looks

3. Nam is not going to take part in my birthday party next week

4. Have you ever do volunteer works?

5. We didn't play football yesterday.