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9 tháng 6 2017

1. I'm sorry I missed Professor Baker's lecture.

I'm sorry not to have heard/ attended Profressor Baker's letter.
..................

2. We may not be able to give the concert.

the concert

.....The concert may have to be cancelled...........

3. I was not surprised to hear that Harry had failed his driving test.

It came...as no surprise ( to me ) that Harry had failed his driving test...................

4. We'd better leave them a note, because it's possible they will arrive later. ( case )

We'd better leave them a note in case they arrive later.

5. Before he came here, he worked for Mr. Smith. ( previous)

Before he came here, his previous boss/ employer was Mr. Smith.

9 tháng 6 2017

1. I'm sorry I missed Professor Baker's lecture.

I'm sorry not to have attended Profressor Baker's lecture.

2. We may not be able to give the concert.

The concert may have to be cancelled.

3. I was not surprised to hear that Harry had failed his driving test.

It came as no surprise to me that Harry had failed his driving test.

4. We'd better leave them a note, because it's possible they will arrive later. ( case )

-> We'd better leave them a note in case they arrive later.

5. Before he came here, he worked for Mr. Smith. ( previous)

-> Before he came here, his previous employer was Mr. Smith.

13 tháng 12 2017

\(\dfrac{1}{1-x}\)+\(\dfrac{1}{1+x}\)+\(\dfrac{2}{1+x^2}\)+\(\dfrac{4}{1+x^4}\)+\(\dfrac{8}{1+x^8}\)+\(\dfrac{16}{1+x^{16}}\)

=

=\(\dfrac{4}{1-x^4}\)+\(\dfrac{4}{1+x^4}\)+\(\dfrac{8}{1+x^8}\)+\(\dfrac{16}{1+x^{16}}\)

=\(\dfrac{8}{1-x^8}\)+\(\dfrac{8}{1+x^8}\)+\(\dfrac{16}{1+x^{16}}\)

=\(\dfrac{16}{1-x^{16}}\)+\(\dfrac{16}{1+x^{16}}\)

=\(\dfrac{32}{1-x^{32}}\)

8 tháng 8 2015

a) Ta có I 2x - 1 I = 2015

=> 2x-1=2015 hoặc 2x-1=2015

+,Th1: 2x-1=2015

             2x=2015+1

             2x=2016

              x=2016:2

             x=1008

+,Th2: 2x-1=-2015

              2x=-2015+1

             2x=-2014

              x=-2014:2

             x=-1007

Vậy x=1008, x=-1007

 

 

|x-1|<5

th1: x-1<5=> x<6

th2: x-1<-5=> x<-4

vậy x <6 hoặc<-4

|x-1|>5 cũng tương tự như thế

còn mấy câu khác Nguyễn Diệu Thảo làm thế chắc bạn cũng biết cách làm rồi

L_I_K_E CHO MÌNH NHA!!!

a) Chương trình bị lỗi

b) Chương trình bị lỗi

c) Chương trình bị lỗi luôn

26 tháng 7 2019

I I  là dấu giá trị tuyệt đối nhé

26 tháng 7 2019

|7 + 5x| = 1 - 4x

=> \(\orbr{\begin{cases}7+5x=1-4x\left(đk:x\le\frac{1}{4}\right)\\7+5x=4x-1\left(đk:x\ge\frac{1}{4}\right)\end{cases}}\)

=> \(\orbr{\begin{cases}7-1=-4x-5x\\7+1=4x-5x\end{cases}}\)

=> \(\orbr{\begin{cases}6=-9x\\8=-x\end{cases}}\)

=> \(\orbr{\begin{cases}x=-\frac{2}{3}\left(tm\right)\\x=-8\left(ktm\right)\end{cases}}\)

|4x- 2x| + 1 = 2x

=> |4x2 - 2x| = 2x - 1

=> \(\orbr{\begin{cases}4x^2-2x=2x-1\left(đk:x\ge\frac{1}{2}\right)\\4x^2-2x=1-2x\left(đk:x\le\frac{1}{2}\right)\end{cases}}\)

=> \(\orbr{\begin{cases}4x^2-2x-2x+1=0\\4x^2-2x-1+2x=0\end{cases}}\)

=> \(\orbr{\begin{cases}\left(2x-1\right)^2=0\\4x^2-1=0\end{cases}}\)

=> \(\orbr{\begin{cases}2x-1=0\\x^2=\frac{1}{4}\end{cases}}\)

=> \(\orbr{\begin{cases}x=\frac{1}{2}\\x=\pm\frac{1}{2}\end{cases}}\)(tm)

Vậy ...

31 tháng 8 2023

???

6 tháng 4 2019

#It's the moment when you're in good mood, you accidentally click back =.=

1) Calculate

\(P=1\frac{1}{3}.1\frac{1}{8}.1\frac{1}{15}....1\frac{1}{63}.1\frac{1}{80}\)

\(=\frac{4}{3}.\frac{9}{8}.\frac{16}{15}....\frac{64}{63}.\frac{81}{80}\)

\(=\frac{2.2}{1.3}.\frac{3.3}{2.4}.\frac{4.4}{3.5}....\frac{8.8}{7.9}.\frac{9.9}{8.10}\)

\(=\frac{2.9}{10}=\frac{9}{5}\)

7 tháng 8 2019

ta có: 10010 + 1 > 10010 - 1

⇒ A = \(\frac{100^{10}+1}{100^{10}-1}< \frac{100^{10}+1-2}{100^{10}-1-2}=\frac{100^{10}-1}{100^{10}-3}=B\)

vậy A < B

19 tháng 12 2015

a) |2x +1| = 7

Th1: 2x + 1 = 7 

<=> x  = 3

Th2: 2x + 1 = -7 

<=> x = -4 

15 tháng 6 2018

\(1)\) Ta có : 

\(\left|2x-1\right|\ge0\)

\(\Leftrightarrow\)\(A=\left|2x-1\right|+8\ge8\)

Dấu "=" xảy ra \(\Leftrightarrow\)\(\left|2x-1\right|=0\)

\(\Leftrightarrow\)\(2x-1=0\)

\(\Leftrightarrow\)\(2x=1\)

\(\Leftrightarrow\)\(x=\frac{1}{2}\)

Vậy GTNN của \(A\) là \(8\) khi \(x=\frac{1}{2}\)

Chúc bạn học tốt ~ 

15 tháng 6 2018

\(2)\) Ta có : 

\(B=\left|x-3\right|+\left|x-9\right|-1\)

\(B=\left|x-3\right|+\left|9-x\right|-1\ge\left|x-3+9-x\right|-1=\left|6\right|-1=6-1=5\)

Dấu "=" xảy ra khi và chỉ khi \(\left(x-3\right)\left(9-x\right)\ge0\)

Trường hợp 1 : 

\(\hept{\begin{cases}x-3\ge0\\9-x\ge0\end{cases}\Leftrightarrow\hept{\begin{cases}x\ge3\\x\le9\end{cases}\Leftrightarrow}3\le x\le9}\)

Trường hợp 2 : 

\(\hept{\begin{cases}x-3\le0\\9-x\le0\end{cases}\Leftrightarrow\hept{\begin{cases}x\le3\\x\ge9\end{cases}}}\) ( loại ) 

Vậy GTNN của \(B\) là \(5\) khi \(3\le x\le9\)

Chúc bạn học tốt ~