1. Is Tom studying for the History test? 
2. Is Mun working today? 
3. Are you writing a letter? 
4. Are they laughing? 
5. Is it raining? 
6. Am I sitting on your chair? 

1.Write questions.Then match them to the answers.

1.(Tom/study).....Is Tom studying...for the History test?                              

2.(Mun/work)..........Is Mun working..................................today?

3.(you/write).............Are you writing..................................a letter?

4.(they/laugh)..........Are they laughing......................?

5.(it/rain) The sky is grey., Is it raining....................................?

6.(I/sit).................Am I sitting.....................................on your chair?

a)góc yoz=xoy-xoz=80-30=50

còn câu b mình nghĩ bạn sai đề r

còn câu c hình như là sai đề nốt vì nếu vẽ vậy thì xot trùng với xoz

mình nghĩ bạn nên xem lại đề đi r có j thì mình giải cho

a, \(\frac{3}{4}x-\frac{1}{5}=\frac{7}{4}x+\frac{11}{5}\)

\(\Rightarrow\frac{3}{4}x-\frac{7}{4}x=\frac{11}{5}+\frac{1}{5}\)

\(\Rightarrow-x=\frac{12}{5}\Rightarrow x=-\frac{12}{5}\)

Vậy ... 

b, \(\frac{x+1}{2}=\frac{8}{x+1}\)

\(\Rightarrow\left(x+1\right)^2=16\)

\(\Rightarrow x+1=4\)hoặc \(x+1=-4\)

\(\Rightarrow x=3\) hoặc  \(x=-5\)

Vậy ..

3/4x-7/4x=1/5+11/5

(3/4-7/4).x=12/5

-1.x=12/5

x=12/5:-1

x=-12/5

vậy x=-12/5

số thích hợp đó là :12

\(\frac{3}{4!}+\frac{3}{5!}+\frac{3}{6!}+...+\frac{3}{100!}=\frac{3}{1.2.3.4}+\frac{3}{1.2.3.4.5}+\frac{3}{1.2.3.4.5.6}+...+\frac{3}{1.2.3.4...100}\)

\(< \frac{3}{2.3.4}+\frac{3}{3.4.5}+\frac{3}{4.5.6}+...+\frac{3}{98.99.100}=\frac{3}{2}.\left(\frac{2}{2.3.4}+\frac{2}{3.4.5}+\frac{2}{4.5.6}+...+\frac{2}{98.99.100}\right)\)

\(=\frac{3}{2}.\left(\frac{1}{2.3}-\frac{1}{3.4}+\frac{1}{3.4}-\frac{1}{4.5}+\frac{1}{4.5}-\frac{1}{5.6}+...+\frac{1}{98.99}-\frac{1}{99.100}\right)\)

\(=\frac{3}{2}\left(\frac{1}{2.3}-\frac{1}{99.100}\right)=\frac{1}{4}-\frac{1}{6600}=\frac{1649}{6600}< \frac{2200}{6600}=\frac{1}{3}\)

cảm ơn bạn Xyz nhiều lắm ,công nhận bn học toán giỏi thiệt đó.Đệ tử xin bái phục!

\(\left(\frac{1}{2}\right)^5.2^5-\left(\frac{1}{2019}-\frac{1}{2020}+\frac{1}{2021}\right)\)

\(=\frac{1^5}{2^5}.2^5-\left(\frac{1}{2019}-\frac{1}{2020}+\frac{1}{2021}\right)\)

\(=\frac{1^5.2^5}{2^5}-\left(\frac{2020.2021}{2019.2020.2021}-\frac{2019.2021}{2019.2020.2021}+\frac{2019.2020}{2019.2020.2021}\right)\)

\(=1^5-\left(\frac{2020.2021-2019.2021+2019.2020}{2019.2020.2021}\right)\)

\(=1-\left(\frac{\left(2020-2019\right).2021+2019.2020}{2019.2020.2021}\right)\)

\(=1-\left(\frac{1.2021+2019.2020}{2019.2020.2021}\right)\)

\(=1-\left(\frac{1+2020+2019.2020}{2019.2020.2021}\right)\)

\(=1-\left(\frac{1+2020.\left(1+2019\right)}{2019.2020.2021}\right)\)

\(=1-\left(\frac{1+2020.2020}{2019.2020.2021}\right)\)

\(=1-\frac{1+2020}{2019.2021}\)

\(=1-\frac{2021}{2019.2021}\)

\(=1-\frac{1}{2019}\)

\(=\frac{2019}{2019}-\frac{1}{2019}=\frac{2018}{2019}\)

Chúc bạn học tốt

a)

Trời âm u mây mưa, biển xám xịt, nặng nề. Trời ầm ầm dông gió, biển đục ngầu, giận dữ...Như một con người biết buồn vui, biển lúc tẻ nhạt,lạnh lùng, lúc sôi nổi,hả hê, lúc đăm chiêu, gắt gỏng...

b) Đoạn văn trên sử dụng phép tu từ so sánh là chủ yếu . Từ ngữ giúp em nhận ra : Như 

TD :Khi quan sát biển thay đổi , tác giả đã liên tưởng đến  sự thay đổi tâm trạng của con người: như con người, biển cũng biết vui, buồn, lúc tẻ nhạt, lạnh lùng, lúc sôi nổi, hả hê, lúc đăm chiêu, gắt gỏng... khiến cho biển như là một con người thật , vô cùng đáng yêu , gần gũi, thân thương.

Chuyển các câu hỏi bắt đầu = từ hỏi (H/WH) sau sang câu bị động .

1. Why didn't they help him ? => Shy/ why wasn't he helped ?

2. How many games has the team played ? => How many games has been played by the team ?

3. Where do people speak English ? => Where is English spoken ?

4. Who are they keeping in the kitchen ? => Who are/ who is being kept in the kitchen ?

5. How can they often this safe ? => How can this safe be opened ?

6. What books are people reading this year ? => What books are being read this yaer ?

7. How did the police find the lost man ? => How was the lost man found by the police ?

8. Who look after the children for you ? => By whom are your children looked affter ? 

9. How long have they waited for the doctor ? => How long has the doctor been waited for ?

10. What time can the boys hand in their papers ? => What time can the boy's papers be handed in ?

11. Who lend you this book ? => By whom is this book lent ?

12. How many marks does the teacher give you ? => How many marks are you given by the teacher ? 

1.We (do) this for you if you want.

-> We will do this for you if you want.

2.If we(need)  some help, we will ask

-> If we need some help, we will ask.

3.If Peter stays with his grandparents,Susan(not be) happy

-> If Peter stays with his grandparents,Susan won't be happy.

4.If we win the money, we (buy) a new house

-> If we win the money, we will buy a new house.

5.She (not write) to you if she leaves.

-> She won't write to you if she leaves.

6.We (go)  on holiday if there is time.

-> We will go  on holiday if there is time.

7. If we  (plant) more trees , the air (be) fresher

-> If we plant more trees , the air will be fresher.

8.If the soil (be) polluted, the vegetables (die).

-> If the soil is polluted, the vegetables will die.

9. Unless he (call) me,I (stay) at home .

-> Unless he calls me,I will stay at home .

10.The weather is not very good. It might (rain) this afternoon.

-> The weather is not very good. It might rain this afternoon.

11.If a student (recycle) the papers,he (save energy).

-> If a student recycles the papers,he will save energy.

12.I (not clean) my room for a long time.

-> I haven't cleaned my room for a long time.

1.We (do)    will do             this for you if you want.

2.If we(need)       need          some help, we will ask

3.If Peter stays with his grandparents,Susan(not be)     won't         happy

4.If we win the money, we ((buy)     will buy          a new house

5.She(not write)    won't write             to you if she leaves

6.We (go)     will go         on holiday if there is time

7. If we     plant    (plant) more trees , the air     will be           (be) fresher

8.If the soil      is      (be) polluted, the vegetables   will die          (die)

9.Unless he     calls         (call)me,I     will stay         (stay) at home 

10.The weather is not very good. It might      rain           (rain) this afternoon

11.If a student     recycles          (recycle) the papers,he   will save energy          (save energy

12.I      haven't clean            (not clean) my room for a long time

* Bạn áp dụng cấu trúc câu đk loại 1 :

| If + thì hiện tại đơn , will + động từ nguyên mẫu |.

Ta có: \(13^{184}=\left(13^4\right)^{46}=\left(\overline{...1}\right)^{46}=\overline{...1}\)

Vì 1 chia cho 5 dư 1 nên 13¹⁸⁴ chia cho 5 dư 1

Số dư của phép chia 13¹⁸⁴ cho 5 sẽ bằng số dư trong phép chia chữ số tận cùng của 13¹⁸⁴ cho 5