Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
1. if you save paper , you will save our Earth
2. if you reuse bottle , you will help the enviroment
3. Turn off the light if you don't use it
4. Have you ever been to America ?
5/ I love reading so I read book every evenings
6. Although I was tired last night , I still have to get up early
1, more beautiful
2, more intelligent
3, longer
4, larger
5, more difficult
6, heavier
7, more important
8, worse
9,better
10, prettier
1/ more beautiful
2/ more intelligent
3/ longer
4/ larger
5/ stronger
6/ heavier
7/ more important
8/ worse
9/ better
10/ more pretty
Bạn tham khảo xem đúng không nka!!!
có [x-y]2=1
suy ra [x-y]mũ 2= 1 mũ 2
suy ra x-1=1
x=1+1
x=2
Gọi d là ƯCLN (2n+1; 2n+3) \(\left(d\inℕ^∗\right)\)
\(\Rightarrow\hept{\begin{cases}2n+1⋮d\\2n+3⋮d\end{cases}}\)
=> (2n+3)-(2n+1) \(⋮\)d
=> 2 \(⋮\)d
Mà d\(\inℕ^∗\)=> d={1;2}
Mà 2n+1 không chia hết cho 2
=> d=1
=> ƯCLN (2n+1;2n+3)=1
=> đpcm
\(12.\left|x+1\right|=36\)
\(\Rightarrow\left|x+1\right|=36:12\)
\(\Rightarrow\left|x+1\right|=3\)
\(\Rightarrow\orbr{\begin{cases}x+1=3\\x+1=-3\end{cases}\Rightarrow}\orbr{\begin{cases}x=3-1\\x=-3-1\end{cases}\Rightarrow\orbr{\begin{cases}x=2\\x=-4\end{cases}}}\)
Vậy \(x=2\)hoặc \(x=-4\)
\(12.\left|x+1\right|=36\)
\(\left|x+1\right|=36:12\)
\(\left|x+1\right|=3\)
\(\Rightarrow\orbr{\begin{cases}x+1=3\\x+1=-3\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=2\\x=-4\end{cases}}\)
Vậy \(x=2\)hoặc \(x=-4\)
Chúc bạn học tốt !!!
Câu 1 :
Ta có : \(A=\frac{10^{100}+1}{10^{101}+1}\)
\(\Rightarrow10A=\frac{10^{101}+10}{10^{101}+1}=\frac{10^{101}+1+9}{10^{101}+1}=1+\frac{9}{10^{101}+1}\)
Ta có : \(B=\frac{10^{101}+1}{10^{102}+1}\)
\(10B=\frac{10^{102}+10}{10^{102}+1}=\frac{10^{102}+1+9}{10^{102}+1}=1+\frac{9}{10^{102}+1}\)
Vì 10101+1<10102+1
\(\Rightarrow\frac{9}{10^{101}+1}>\frac{9}{10^{102}+1}\)
\(\Rightarrow1+\frac{9}{10^{101}+1}>1+\frac{9}{10^{102}+1}\)
\(\Rightarrow\)10A>10B
\(\Rightarrow\)A>B
Vậy A>B.
Câu 2 :
Ta có : \(E=\frac{2000+2001}{2001+2002}=\frac{2000}{2001+2002}+\frac{2001}{2001+2002}\)
Vì 2001<2001+2002 và 2002<2001+2002
\(\Rightarrow\hept{\begin{cases}\frac{2000}{2001}>\frac{2000}{2001+2002}\\\frac{2001}{2002}>\frac{2001}{2001+2002}\end{cases}}\)
\(\Rightarrow C>E\)
Vậy C>E.
Để A nhận giá trị nguyên thì n + 1 \(⋮\)n - 2
\(\Rightarrow\left(n-2\right)+3⋮n-2\)
\(\Rightarrow n+2\inƯ_{\left(3\right)}=\left\{\pm1;\pm3\right\}\)
Ta lập bảng :
| n+2 | 1 | -3 | -1 | 3 |
| n | -1 | -5 | -3 | 1 |
Vậy : n \(\in\left\{-5;-3;-1;1\right\}\)
Từ đề bài, ta suy ra:
\(\frac{n+1}{n-2}=\frac{n-2+3}{n-2}=\frac{n-2}{n-2}+\frac{3}{n-2}=1+\frac{3}{n-2}\)
Vì 1 \(\in\)Z nên để A nguyên thì 3\(⋮\)(n-2) hay (n-2)\(\in\) Ư(3)
<=> (n-2)\(\in\){-1;1;-3;3}
Xét các trường hợp:
Nếu n-2=-1<=> n=1
Nếu n-2=1<=> n=3
Nếu n-2=3<=> n=5
Nếu n-2=-3 thì n=-1
Vậy n\(\in\){1;3;5;-1}
1. Robots will be able to do all the housework instead of us
2. Turn off the light when you don't use it.
3. Mr. Van ran very fast when she was young.
1 robots will be able to do all the house work instead of us
2 turn off the light when you don't use
3 Mr van ran very fast when he was young
cho mik nhé :)