10-897eerret667

công thức để làm :10ⁿ+8=9.11...112 (có n-1 chữ số 1, n>1)

a chia hết cho bⁿ thì a phải chia hết cho b

11...12 luôn ko chia hết cho 7 (n chữ số 1 , n khác 2 )

ta có: 10²⁰²¹+8=9.11...112(2020 chữ số 1)

vì 9 ko chia hết cho 7 , 11...112 ko chia hết cho 7 và (9,11...12)=1 suy ra 9.11...112 ko chia hết cho 7 suy ra 10²⁰²¹+8 ko chia hết cho 7 suy ra điều cm trên là sai

nếu mình sai cho mình xin lỗi nha

suy7 nha

Dear Anne(Hà Lam).

I received your email last week, in which you asked me about my city New York in 2050. There are different ideas about this question. I thought it in a few days, and now I can give you two predictions.

Let's take a look at an optimis viewpoint. In 2050 New York will become a more liveable city than ever before for lots of reasons. The city authorities have built a very careful plan to promote self-driving electric taxis to deal with crowded public transport. In addition, the city dwellers are encouraged to use city's building roofs for gardens fertilised with compose in order to recycle rubbish and reduce pollution. The government will also build offshore windfarms to replace ageing electricity network.

On the other hand, pessimis people think that the city life won't be a safe place to live in because the government cannot control the use of guns, and therefore the crime rate will be higher. People's life will also continue to be threatened because of natural disasters such as floods, storms, earthquakes. The effects of global warming have great impacts on the city dwellers.

That's all about my answer to your question. I hope you will be satisfied with it, Nam.

Best wishes,

Wonie(Quyên)

tham khảo ạ

Dear Bich

Your last email asked me about my city Ha Noi in 2050. Well, but I'm busy and have no time to reply you soon. Today I am writing to you about that question. There are different ideas about this question. I thought about it in a few days, and now I can give you some predictions.

Let's take a look at optimis aspects. In 2050 Ha Noi will become a more modern city for lots of reasons. High technology has been applied in our lives. The robots will replace us for many jobs such as manufacturing, farming, etc. Smart cars which will be commonly used in the road. They will help human beings to decrease the accidents as well as traffic jams.

On the contrary, pessimis people think that the city life will be a dangerous place to live in because the environment is completely polluted. The effects of global warming have great impacts on the city dwellers, higher temperature in the summer and colder climate in the winter. There are a lot of means of transport so that emission from them cause air pollution. Our health will be threatened because of low air quality index.

That's all about my thoughts about your question. I hope you will be satisfied with it, Bich.

Best wishes,

Chau

2,5 x 7,2 = 10 x 7,2 : 4 

              = 72 : 4

              = 18.

Muốn tính phép tính này ta làm như sau :

Ta lấy 10 x 7,2 :4 =18

VẬY KẾT QUẢ LÀ 18

Our travel brochure is about an eco tour to Central Highlands. The tour leaves the ABC office at 5 a.m. every Saturday and gets back at 8 p.m. the next day. The two-day tour doesn’t cost too much: only VND 900,000 per person. During this trip, you can go biking in the forest and watch wildlife. You can also visit Don village, enjoy cooking and staying overnight with local ethnic families. If we have enough time, we may visit coffee plantations to enjoy fresh coffee. But you need to behave responsibly. You should speak softly while watching the animals. And remember to respect local people's life and not to litter.

Mông cô chấm điểm cho em ạ!Cảm ơn cô.

Chép mạng vừa thôi bạn Mỹ Châu ơi!

https://tech12h.com/de-bai/use-information-about-eco-tours-sa-pa-or-central-highlands-speaking-section-design-travel

Thưa cô đây là link ạ, cô có thể vào thống kê của em để dùng

\(a.a=3,b=0,c=7\)

\(b.a=2,b=0,c=0,d=8\)

\(c.a=1,b=9,c=6,d=7\)

\(d.a,b\in\left\{\varnothing\right\}\) (tức là không có số nào thỏa mãn đề bài)

49/60= 1/60+1/60+1/60+1/60+.....+1/60.

Vì 1/60 > 1/11; 1/60>1/12;... nên 1/11+1/12+1/13+1/14+...+1/25 > 1/60

9 nha bạn

1 ống dài và 30 ống ngắn

1 dài 3 ngắn

9 , 99690

TH2 có hơi sai sai nhé..

( Đ hiểu kiểu gì mà mấy bạn cứ trả lời TH2, thôi thì mình sửa lại vậy =)) )

TH2 : a = 2 - b => a² = b² - 4b + 4. Thay vào (**) ta có :

a² - b² = 2x <=> - 4b + 4 = 2x

<=> - 2b = x - 2

<=> 4b² = x² - 4x + 4

<=> 4 - 4x = x² - 4x + 4

<=> x² - 4x + 4 + 4x - 4 = 0

<=> x² = 0 <=> x = 0 (tmđk)

Vậy pt có tập nghiệm S = { - 3/5 ; 0 }