Số tiền lãi là:

         24200000:100.21=5082000(đồng)

                      số tiền vốn là:

           24200000-5082000=19118000(đồng)

                     Đ/s:19118000 đồng

Ta có công thức : Giá = vốn + lãi 

Tỉ số phần trăm của vốn so với giá là:

100% - 21% = 79% (giá)

Vốn để mua hàng là:

24 200 000 x 79 : 100 = 19 118 000 (đồng)

Đáp số: 

Tỉ số phần trăm của vốn so với giá là:

100% - 21% = 79% (giá)

Vốn để mua hàng là:

24 200 000 x 79 : 100 = 19 118 000 (đồng)

đ/s:...

Vậy, 7x + 36 = 12 - x

=> 8x + 36 = 12

<=> x = (12 -36) ÷ 8 = -3

\(2\left(x+3\right)-4x=48\)

\(=>2x+6-4x=48\)

\(=>-2x=48-6\)

\(=>-2x=42\)

\(=>x=-21\)

Lệ Tự Nguyên Hào sai rồi nha

NguYen Tuan Anh oi, bn Hào giúp mk sua câu mk đăng đầu tiên đó bn

Bn í giải đúng rùi. Hì hì

Giá tiền của chiếc xe đạp là:

(15:100)×400=60 đồng

Thêm hàng nghìn dùm chị nha, bớt đi cho dễ tính ấy mà chị quên mất không ghi😥

                         Bài giải 

giá tiền của chiếc xe đạp bây giờ là :

(15 : 100 ) x 400 = 60 000 (đồng)

câu a: n =1

câu b: n =2

Bài 22:

a) Ta có: \(A=\dfrac{1}{1\cdot2}+\dfrac{1}{2\cdot3}+\dfrac{1}{3\cdot4}+...+\dfrac{1}{2017\cdot2018}\)

\(=1-\dfrac{1}{2}+\dfrac{1}{2}-\dfrac{1}{3}+\dfrac{1}{3}-\dfrac{1}{4}+...+\dfrac{1}{2017}-\dfrac{1}{2018}\)

\(=1-\dfrac{1}{2018}=\dfrac{2017}{2018}\)

\(x^2-25+y^2+2xy\)

\(=\left(x^2+2xy+y^2\right)-25\)

\(=\left(x+y\right)^2-5^2\)

\(=\left[\left(x+y\right)-5\right]\left[\left(x+y\right)+5\right]\)

\(=\left(x+y+5\right)\left(x+y-5\right)\)

\(x^2-25+y^2+2xy\) 

\(=\left(x^2+2xy\right)\left(y^2-25\right)\) 

\(=\left(x+y\right)^2\left(y-5\right)\left(y+5\right)\) 

`x^2 - 25 + y^2 + 2xy

`= x^2 + 2xy + y^2 - 25

`= (x^2 + 2xy + y^2) - 5^2`

`= (x^2 + xy + xy + y) - 5^2`

`= [x(x+y) + y(x+y)] - 5^2`

`= (x+y)(x+y) - 5^2```

`= (x+y)^2 - 5^2`

`= (x+y-5)(x+5+5)`

Gen A quy định tính trạng trội mắt đen

____a_________________lặn____đỏ

Cá kiếm mắt đỏ có KG: aa

Vì F₁ phân li theo tỉ lệ 1 đen : 1 đỏ

→ Cá kiếm mắt đen có KG: Aa

Sơ đồ lai:

P: Mắt đen X Mắt đỏ

________Aa_______aa______

G:_______A;a______a__________

F₁: 1 Aa:1aa

TLKH F₁: 1 đen : 1 đỏ

1.I think you ought to give up playing video games. (should)

-->I think you should give up playing video games.

2.It's necessary for me to finish the work on time. (have to)

--->I have to finish the work on time.

3.It wasn't necessary for you to clean that car. (have to)

--->You didn't have to clean that car.

4.It was quite unnecessary for you to adopt a green lifestyle. (have to)

---->You didn't have to adopt a green lifestyle.

5.It was careless of you to leave the windows open last night. (shouldn't)

----->You shouldn't have left the windows open last night.

6.It is advisable for each member in the family to share the housework equally. (should)

---->Each member in the family should share the housework equally.

7.You are required to come back home before 10 p.m. (must)

--->You must come back home before 10 p.m.

8.Lina is advised to prepare carefully in the morning. (should)

----->Lina should prepare carefully in the morning.

9.Tu is responsible for picking up litter. (have to)

------>Tu has to pick up litter.

1.You are required to ask your parents for permission before staying out late. (must)

You must ask your parents for permission before staying out late.

2.I think you ought to give up smoking immediately. (should)

I think you should give up smoking immediately.

3.It is not a good idea for me to stay up late. (shouldn't)

I shouldn't stay up late.

4.It wasn't necessary for you to send these letters. (have to)

You didn't have to send these letters.

5.It was unnecessary for Tim to finish the work. (have to)

Tim didn't have to finish the work.

6.It was careless of you to leave your children alone at home. (shouldn't)

You shouldn't have left your children alone at home.

Bằng 1 cách nào đó 1 câu hỏi từ 2023 ở đây và tôi vẫn trả lời nó sau 1 năm :v

II

1 B

2 A

3 A

4 D

5 B

6 B

7 A

8 D

9 D

10 D

1 B

2 C

3 A

4 D

5 D

6 B

7 D

8 C

9 A

10 B

1 Japanese is too difficult for me to learn

2 If he felt well, he wouldn't go to bed early

3 I wish I hadn't gone out in the rain

4 They had me carry te box upstairs

5 Your sister is too young to enjoy this film

6 THey had this letter posted by me

7 The morning was too cold for them to go out

8 If the tickets were cheap enough, we would go there

9 The pupils collected these old clothes

10 The coffee is so excellent so I can drink it

11 Her house was sold 2 years ago

12 Some tickets was bought there by him

13 Waste paper was recycled to save money and labour

14 The TV set was so heavy that the girl couldn't move it

15 I will have someone type the report for you

16 There was so much fog that the driver couldn't see far

17 THe day was fine enoigh for them to enjoy sunbathing on the beach

18 I wish your were here now

19 Susan offeref me to lend her some money

20 They asked me is I could fill in the form

21 The acrobat whom we saw on TV last night is his uncle

22 The traffic jam prevented us from coming late

23 It is sucha wide gate that the struck can't get through it

24 Thet novel was written by Charales Dickens

25 Your answer is too difficult for me to answer

26 We've had so much homework that we can't find time to go out

27 He can't borrow the book because he don't have the library card

28 If the buses weren't full up, they would stop

29 She is not strong enough to carry her luggage

30 The dog which is playing with a ball is a big one