nearest

nearest

a: Xét ΔADI và ΔAEI có

AD=AE

\(\widehat{DAI}=\widehat{EAI}\)

AI chung

DO đó: ΔADI=ΔAEI

Suy ra: DI=EI

hay I là trung điểm của DE

b: Xét ΔNID vuông tại I và ΔNIE vuông tại I có 

NI chung

ID=IE

Do đó: ΔNID=ΔNIE

Suy ra: ND=NE

e cần câu c ạ :(((

a) \(\Leftrightarrow x^2=\sqrt{4}\)

\(\Leftrightarrow x^2=2\Leftrightarrow x=\pm2\)

b) \(\Leftrightarrow\sqrt{\left(\dfrac{1}{2}x+1\right)^2}=9\)

\(\Leftrightarrow\left|\dfrac{1}{2}x+1\right|=9\)

\(\Leftrightarrow\left[{}\begin{matrix}\dfrac{1}{2}x+1=9\\\dfrac{1}{2}x+1=-9\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}x=16\\x=-16\end{matrix}\right.\)

c) \(\Leftrightarrow\sqrt{2x}-4\sqrt{2x}+16\sqrt{2x}=52\left(đk:x\ge0\right)\)

\(\Leftrightarrow13\sqrt{2x}=52\Leftrightarrow\sqrt{2x}=4\Leftrightarrow2x=16\Leftrightarrow x=8\left(tm\right)\)

f: Ta có: \(\sqrt{\dfrac{50-25x}{4}}-8\sqrt{2-x}+\sqrt{18-9x}=-10\)

\(\Leftrightarrow\sqrt{2-x}\cdot\dfrac{5}{2}-8\sqrt{2-x}+3\sqrt{2-x}=-10\)

\(\Leftrightarrow\sqrt{2-x}=4\)

\(\Leftrightarrow2-x=16\)

hay x=-14

a: Theo đề, ta có hệ phương trình:

\(\left\{{}\begin{matrix}-a+b=-20\\3a+b=8\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}a=7\\b=8-3a=8-3\cdot7=-13\end{matrix}\right.\)

`1,14 . 6,4 + 1,14 . 3,6 + 0,2 . 1,14 . 5`

`= 1,14 . (3,6 + 6,4 + 1)`

`= 1,14 . 11`

`= 12,54`

có đúng ko ạ

sao e thử lại bằng máy tính lại sai ạ

Internet can be considered as one of the greatest inventions of mankind in the 20th century. All of the things that Internet had been given us have never stopped the world from being surprised. With an extremely huge database of information and has been constantly updated every day, it is true to say that the Internet is an ocean of ​​knowledge which is never exhausted. The big men who dominate the Internet including Google, Wikipedia, YouTube, Facebook, Twitter, Instagram etc., and they can satisfy almost all of the curiosity of anyone. We can find almost every information, from society, science, astronomy, geography to methods for cooking, make-up, or even personal information of a person who is completely a stranger to us. Internet provides an effective learning and researching environment if we know how to use it suitably. Besides studying, we can also search interesting resources of entertainment on the websites. Nowadays, most of the entertainment programs are posted online in large numbers, so it will not be difficult for us to find joy for ourselves. In short, the Internet is a powerful assistant for finding and sharing information for people.

Internet has made everyone’s life very easy and simple as we no longer need to go outside for paying bill, shopping, seeing movie, business transactions, etc. It has been an essential part of our life means we can say that without it we face lots of problems in our daily lives. Because of its easiness and usefulness, it is used everywhere such as workplace, offices, schools, colleges, banks, education institutions, training centres, shops, railways station, airports, restaurants, hotels, malls, and most importantly at home by each members for different purposes.

Once we take the internet connection by paying money to the Internet Service Provider, we can access the internet facility anytime from any corner of the world for one week or month according to the internet plan we have taken.

From the time internet has come in our life, our world has become changed to a great extent in the positive ways however in the negative ways too. It is highly beneficial for the students, businessmen, government agencies, research organizations, etc. Students can search any needed information for their study, businessmen can deal their business matters from one place, government agencies can do their work in proper time, research organizations can research more and give outstanding results, etc.

Đổi: 300m2 = 3000000cm2

Diện tích 1 viên gạch là:

50 x 50 = 2500 (cm2)

Vậy số viên gạch có là:

3000000 : 2500 = 1200 (viên)

Đ/S: 1200 viên