Exercise 6

1. He said his father hadn't gone there the day before

2. She asked him when she could start her work

3. We are planning to visit Ho Chi Minh city

4. She enjoys running in the morning

5. If the weather isn't good, I won't go out

6. How long has she worked for the company? For 5 years

7. We spent five years building monument

8. It took him one hour and a half to finish homework

9. If I were 10 years younger, I would change my job

10. I didn't go shopping last week

Exercise 2
1. some cake - her son

2. a car - Pedro

3. money - charity

4. a teddy bear - Laura

5. a house - poor children

6. a good job - Marcos

7. a letter - my boyfriend

8. a letter - his wife

9. a new house - me

10. a report - the company

11. her friend - an email

12. you - your homework

13. them - a bag of full money

14. a book - the French revolution

15. your help

Tân ngữ trực tiếp là từ đầu tiên, sau dấu gạch là tân ngữ gián tiếp nha

\(\sqrt{12}-\sqrt{27}+\sqrt{48}=2\sqrt{3}-3\sqrt{3}+4\sqrt{3}=3\sqrt{3}\)

xem lại đề câu 4 nha bạn

Bài 4:

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

2) \(\left(x-3\right)^2-x^2+10x-7=x^2-6x+9-x^2+10x-7=4x+2\)

3) 

\(\left(x+2\right)^2-\left(x-3\right)\left(x+1\right)\\ =x^2+4x+4-\left(x^2+x-3x-3\right)\\ =x^2+4x+4-x^2-x+3x+3\\ =6x+7\)

4) \(\left(x+4\right)\left(x-2\right)-\left(x-3\right)^2\)

\(=x^2-2x+4x-8-\left(x^2-6x+9\right)\\ =x^2+2x-8-x^2+6x-9\\ =8x-17\)

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

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

6) \(\left(x+3\right)\left(x-3\right)-x\left(23+x\right)\)

\(=x^2-9-23x-x^2=-23x-9\)

7) \(\left(1-2x\right)\left(5-3x\right)+\left(4-x\right)^2\)

\(=5-3x-10x+6x^2+16-8x+x^2\\ =7x^2-21x+21\)

8) \(\left(x-2\right)\left(x+2\right)-\left(x-3\right)\left(x+1\right)\)

\(=x^2-4-\left(x^2+x-3x-3\right)\\ =x^2-4-x^2-x+3x+3\\ =2x-1\)

Số các số hạng

\(\left(\dfrac{861-1}{4}\right)+1=216\)

Tổng dãy số

\(\left(861+1\right).216:2=93096\)

Ta thấy tổng của \(9+3+0+9+6=27⋮3\)

=> Biểu thức A chia hết cho 3

a, Xét tứ giác ABMD có

AB // DM (do hình thang ABCD có AB // CD)

AB = DM (do \(AB=DM=MC=\dfrac{CD}{2}\))

=> Tứ giác ABMD là hình bình hành

=> AD // BM (đpcm)

b, Xét tứ giác ABCM có

AB // CM (do ABCD là hình thang)

AB = MC (cm câu a)

=> Tứ giác ABCM là hình bình hành

=> AM // BC

\(\exists x\in R:x^2-2x< 0\)

\(\exists x\in R:\left(x^2+x\right)⋮̸3\)

\(\forall n\in N:\left(n^2+1\right)⋮̸3\)

\(\exists x\in N:\left(x^2+x\right)⋮̸2\)

\(\forall y\in R:9y^2-3\ne0\)

Ex2

1. much

2. many

3. many

4. much

5. many

6. much

Ex 3

2. a lot

3. much

4. a little

5. many

6. a few

1B (cause sb to do sth)

2B (being taken in: bị lừa)

3A (encourage to V)