\(M=\dfrac{2x+5}{x+1}\in Z\)

\(\Rightarrow2x+5⋮x+1\)

\(\Rightarrow2x+5-2\left(x+1\right)⋮x+1\)

\(\Rightarrow2x+5-2x-2⋮x+1\)

\(\Rightarrow3⋮x+1\)

\(\Rightarrow x+1\in U\left(3\right)=\left\{-1;1;-3;3\right\}\)

\(\Rightarrow x\in\left\{-2;0;-4;2\right\}\)

Để M là số nguyên thì \(2x+5⋮x+1\)

=>\(2x+2+3⋮x+1\)

=>\(3⋮x+1\)

=>\(x+1\in\left\{1;-1;3;-3\right\}\)

=>\(x\in\left\{0;-2;2;-4\right\}\)

\(\dfrac{4}{x}+\dfrac{2}{y}=1\) \(\left(x;y\ne0\right)\)

\(\Rightarrow2x+4y=xy\)

\(\Rightarrow2x-8+4y-xy=-8\)

\(\Rightarrow2\left(x-4\right)-y\left(x-4\right)=-8\)

\(\Rightarrow\left(x-4\right)\left(y-2\right)=8\)

\(\Rightarrow\left(x-4;y-2\right)\in U\left(8\right)=\left\{-1;1;-2;2;-4;4;-8;8\right\}\)

\(\Rightarrow\left(x;y\right)\in\left\{\left(3;-6\right);\left(5;10\right);\left(2;-2\right);\left(8;4\right);\left(-4;;1\right);\left(12;3\right)\right\}\)

Cô ấy thích hát hơn nhảy múa

She prefers singing to dancing.

Câu của bạn gần đúng, nhưng cần một chút điều chỉnh. Câu chính xác là:

Fruit is a convenient source of vitamins and energy.

Lý do:

• Bỏ "The" trước "Fruit" vì câu này không cần mạo từ xác định.
• Thay "be" bằng "is" để phù hợp với thì hiện tại đơn.
• Thêm "a" để chỉ một loại đối tượng trong nhóm.

thêm "the" sau từ is nhé bạn!

Ex. 11 :

1. take -> takes

2. never is -> is never

3. waking -> wakes

4. has been -> was

5. will go -> go

6. aren't -> isn't

7. interested on -> interested in

8. as well as -> as soon as

9. keen into -> keen on

10. is -> are

11. telling -> to tell

12. what happened -> what had happened

13. was keen about -> was keen on

14. probably will -> will probably

15. will -> will be

Ex.12 :

1. I'm keen on maths.

2. Unless you listen, you won't follow the teacher's lecture.

3. We are interested in walking in the rain

4. Should you ask me for the car, i will lend it to you.

5. John spends 30 minutes to walk to school.

6. She's fond of playing cards with her children at the weekend.

7. She's interested in taking photos of her children.

8. We don't have any time to prepare the speech.

9. I promise I will phone you next week.

10. I am fond of watching the goldfish in the tank.

11. My mon isn't passionate about preparing meals.

12. He fancies reading comic books.

13. I think not many people are into listening to music in their free time.

14. Should he studies hard, he will pass the exam.

15. If you go out in the rain, you will get wet.

.............

câu a mik làm đc rồi nhe CM c-g-c

a: Ta có: \(AB=\dfrac{BC}{2}\)

\(BE=EC=\dfrac{BC}{2}\)

Do đó: AB=BE=EC

Xét ΔBAD và ΔBED có

BA=BE

\(\widehat{ABD}=\widehat{EBD}\)

BD chung

Do đó: ΔBAD=ΔBED

b: ΔBAD=ΔBED

=>\(\widehat{BAD}=\widehat{BED}\)

=>\(\widehat{BED}=90^0\)

=>DE\(\perp\)BC

c: Xét ΔDBC có

DE là đường cao

DE là đường trung tuyến

Do đó: ΔDBC cân tại D

=>DB=DC

d: ΔDBC cân tại D

=>\(\widehat{DBC}=\widehat{DCB}\)

mà \(\widehat{ABC}=2\cdot\widehat{DBC}\)(BD là phân giác của góc ABC)

nên \(\widehat{ABC}=2\cdot\widehat{ACB}\)

ΔABC vuông tại A

=>\(2\cdot\widehat{ACB}+\widehat{C}=90^0\)

=>\(3\cdot\widehat{C}=90^0\)

=>\(\widehat{C}=\dfrac{90^0}{3}=30^0\)

\(\widehat{B}=2\cdot30^0=60^0\)

Ex4

1 B

2 A

3 C

4 A

5 C

6 B

7 B

8 D

9 C

10 B

Ex5

1 D

2 A

/

@NQH . Bạn k spam câu trl!

1 The house has just been cleaned

2 The bike has been repaired by my father

3 The exercises have been done since 6 o'clock

4 The girl has already been seen

5 The flowers have been picked by Daisy

6 The chicken has been raised by Nam for 3 months

7 The book has been read before

8 The room has been decorated since this morning

9 The oranges have been eaten

10 A new car has just been bought by her father

------------------------

1 The thief has been arrested since last week

2 The dogs have been raised for 5 years

3 The student have just been met by me

4 The comedy has been shown here

1. She has just cleaned the house.

   • The house has just been cleaned by her.

2. My father has repaired the bike.

   • The bike has been repaired by my father.

3. They have done the exercises since 6 o'clock.

   • The exercises have been done by them since 6 o'clock.

4. He has already seen the girl.

   • The girl has already been seen by him.

5. Daisy has picked the flowers.

   • The flowers have been picked by Daisy.

6. Nam has raised the chicken for three months.

   • The chicken has been raised by Nam for three months.

7. I have read the book before.

   • The book has been read by me before.

8. She has decorated the room since this morning.

   • The room has been decorated by her since this morning.

9. Someone has eaten the oranges.

   • The oranges have been eaten by someone.

10. Her father has just bought a new car.

    • A new car has just been bought by her father.

1. The thief/ arrest / since last week.

   • The thief has been arrested since last week.

2. The dogs/ raise/ for/ five years.

   • The dogs have been raised for five years.

3. The student/ just/ meet/me.

   • I have just been met by the student.

4. The comedy/ show/here.

   • The comedy show has been shown here.