\(=(a^{2}-8ab+16b^{2})-9\)

\(=(a-4b)^{2}-3^{2}\)

\(=(a-4b-3)(a-4b+3)\)

1.\(x^{2}-xy-2x+2y\)

\(=x(x-2)-y(x-2)\)

\(=(x-y)(x-2)\)

2.\(x^{2}-9y^{2}+6y-1\)

\(=x^{2}-(9y^{2}-6y+1)\)

\(=x^{2}-(3y-1)^{2}\)

\(=(x+3y-1)(x-3y+1)\)

important

1. C

2. A

3. C 

4. C 

5. A

6. C 

7. B 

8. C

9. A 

10. C

Could you show me the way ___________ the temple?

A. in

B. at

C. of

D. to

invention - inventor

Adj của success là successful

1.for

2.beautiful

3.behind

4.tress

5.photo

Đổi 4 tấn = 4000 (kg)

Số kg gạo đựng trong 10 bao to là: 50 x 10 = 500 (kg)

Số kg vào đựng trong mỗi bao nhỏ là : (4000 - 500) : 100 = 35 (kg)

1C

2A

3A

4B

1. arrived / was still sleeping

2. went / were having

3. was having / stopped

4. came / was working

5. were crossing / saw

6. saw / was standing

7. were playing / came

8. rang / was taking

9. was sitting / saw

10. were cleaning / came