trả lời đầy đủ nha các thím :d :D
 

1.He said: “I shall expect her”

->he said he should expect her

2.He said: “I can’t find my hat”

-> he said he couldn't find his hat

3.She said: “I am going to the movies tomorrow”

-> she said she was going to the movies the next day

4.Lan said to me: “You are looking much better”

-> lan told me i was looking much better

5.He says: “The river is rising early this year”

-> he says the river was rising early that year

6.She said to me: “I will do it if necessary I can”

-> she told me she would do it if necessary she could

7.He said to his friend: “Did you see the accident yesterday?”

-> he told his friend if he had seen the accident the day before

8.John said to me: “How did you come here?”

-> John told me How i had come there

9.He said: “Have you finished your task, Nam?

->he told Nam if he had finished his task

10.He said: “Yesterday evening I met Nam. He has bought a new car''

-> he said the day before evening he had met Nam . he had bought a new car

11.She said to me: “Who is this book?”

-> she told me Who that book was

12.Nam said to his father: “Please let me go to Paris”

-> Nam told his father to go to Paris

13.He said to me: “Do you like to live in Orange Country?

-> he told me if i like to live in Orange country

14.My friend asked me: “ Have you a lot of money?”

-> My friend asked me if i had a lot of money

15.He said: “I can’t meet you here either today or tomorrow”

16.They said: “We did it yesterday”

-> they said they had done it the day before

17. ‘ If I were you, I’d read the exam questions very carefully.’ Teacher said

->Teacher advised Minh to read the exam questions very carefully

18. ‘ You had better not waste your time, Betty.’ Tom said.

Tom advised betty not to waste her time

19. “Shut the door but don’t lock it”, I said to him.

I told him to shut the door

20. ‘ I image I’ll see Sue at the party.’ john said

John hoped to see sue at the party

21. ‘ Don’t forget to give the book to Jane’ David said

->David reminded not to forget to give the book

22. Before Tim went to bed, his father said, ‘Don’t forget to brush your teeth.’

Before Tim went to bed, his father reminded not to forget ...................

23." Is this your new calculator, Mai?" Nam asked.

Nam asked mai if that her new calculator was

24." Tell me what you saw at the party yesterday?" I said to Tom .

I told tom to tell me wwhat he had seen at the party the day before

pt (1) có \(\Delta'\)= (-m)²-m+2= m²-2.\(\dfrac{1}{2}\).m + \(\dfrac{1}{4}-\dfrac{1}{4}\)+2 = ( m-\(\dfrac{1}{2}\))²+\(\dfrac{7}{4}\)

nhận thấy : ( m-\(\dfrac{1}{2}\))² \(\ge\)0\(\forall\)m

==> ( m-\(\dfrac{1}{2}\))²+\(\dfrac{7}{4}\)\(\ge\)\(\dfrac{7}{4}\)>0

==> \(\Delta'\)>0 ==> pt (1) luôn có 2 nghiệm phân biệt

theo hệ thức vi ét ta có :\(\left\{{}\begin{matrix}x1+x2=2m\\x1.x2=-2\end{matrix}\right.\)(2)

mà M=\(\dfrac{-24}{x1^2+x2^2-6x1x2}=\dfrac{-24}{\left(x1+x2\right)^2-8x1.x2}\)

thay (2) vào M ta đc M=\(\dfrac{-24}{\left(2m\right)^2-8\left(m-2\right)}=\dfrac{-24}{4m^2-8m+16}=\dfrac{-24}{\left(4m^2-8m+4\right)+12}=\dfrac{-24}{\left(2m-2\right)^2+12}\)

nhận thấy (2m-2)²+12 \(\ge\)12

==> M \(\ge\)-2

dấu ''=,, xảy ra <=> m=1

vậy.......................

100 , ủng hộ mk nha

tính dtich nào vậy b?

Gọi tgian người làm biếng làm mk thì hthanh là x (h) (x>6)

trong 1 h người làm siêng làm đc : \(\dfrac{1}{10}\) (công việc )

người làm biếng làm đc : \(\dfrac{1}{x}\) (công việc )

cả 2 người làm trong 6h nên trong 1h cả 2 người làm đc \(\dfrac{1}{6}\) ( cviec )

theo bài ta có pt : \(\dfrac{1}{x}+\dfrac{1}{10}=\dfrac{1}{6}\)

==> \(\dfrac{1}{x}=\dfrac{1}{6}-\dfrac{1}{10}=\dfrac{1}{15}\)

==> x=15 (t/m đk )

vậy........

1332 nha bn tang bn

có : (x-y)² \(\ge0,\forall x,y\)

==>x²-2xy+y² \(\ge\)0 \(\forall x,y\)

==> 2.(x²+y²)\(\ge\)2xy +x²+y² \(\forall x,y\)

==> x²+y² \(\ge\)\(\dfrac{\left(x+y\right)^2}{2}=\dfrac{2^2}{2}=2\) ( do x+y=2) \(\forall x,y\)

lại có (x^2-y²)²\(\ge\)0\(\forall x,y\)

==> x⁴+y⁴-2x²y² \(\ge\)0 \(\forall x,y\)

==> 2.(x⁴+y⁴) \(\ge\)2x²y² + x⁴+y⁴ \(\forall x,y\)

==> x⁴+y⁴ \(\ge\)\(\dfrac{\left(x^2+y^2\right)^2}{2}\ge\dfrac{2^2}{2}=2\)

==> đpcm

dấu ''=,, xảy ra <=> \(\left\{{}\begin{matrix}x+y=2\\x-y=0\\x^2-y^2=0\end{matrix}\right.< =>x=y=1}\)