1I didn't arrive in time to see her
I wasn't early enough to see her
2. . We couldn't drive because of the fog
The fog prevented us from driving
3. A train leaves at eight o'clock every morning
There is an eight-o'clock train every morning
4. . John asked if it was the blue one or the green she wanted
Which. do you want, the blue one or the green? John asked her
5. I haven't eaten this kind of food before
This is the first time I have earen this kind of food
6. She started working as a secratary five years ago
She has .worked as a secratary for five years 
7. " Why don't you put your luggage under the seat?"he asked
He suggested that I put my luggage under the seat
8. I'm sure you didn't lock the front door. Here is the key
You can't have locked the front door
9. He couldn't repair the broken vase.
The vase couldn't be repaired by him
10. I started work for the company a year ago
I've been working for the company for a year

rút gọn thừa số chung:
2.1x=1+(-1)1+1x^2

đơn giàn biểu thức:
-1+(-1)((-1)1)+2.1x+(-1)(1x^2)=0

giải phương trình:
-(1x^2-2.1x-1+10=0

giài phương trình

1x^2-2.1x-1+1=0

BẠN NHỚ VẼ ĐỒ THỊ HÀM SỐ ĐỂ TIỆN LÀM BÀI NHÉ...MÌNH KHÔNG BIẾT VẼ NHƯ THẾ NÀO TRÊN ONLINE MATH NÊN BẠN VẼ ĐƯỢC MÀ...LỚP 9 RỒI...mình học lớp 7..tich cho mình nha

A, bạn ơi mình biết làm hết r

B,cài này dễ lằm bạn nghĩ đi okeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

a) \(\left|\left|x-1\right|-1\right|=2\Rightarrow\orbr{\begin{cases}\left|x-1\right|-1=2\\\left|x-1\right|-1=-2\end{cases}}\Rightarrow\orbr{\begin{cases}\left|x-1\right|=3\\\left|x-1\right|=-1\left(l\right)\end{cases}}\)

TH1: x - 1 = 3

         x      = 4

TH2: x - 1 = - 3

        x       = - 2 

b) Tương tự câu a.

c) \(\left|\left|2x-3\right|-x+1\right|=42-8\)

\(\left|\left|2x-3\right|-x+1\right|=34\)

TH1: \(\left|2x-3\right|-x+1=34\)

\(\left|2x-3\right|-x=33\)

Với \(x\ge\frac{3}{2}\), ta có \(2x-3-x=33\Rightarrow x=36\)  (tm)

Với \(x< \frac{3}{2}\), ta có \(3-2x-x+1=34\Rightarrow-3x=30\Rightarrow x=-10\left(tm\right)\)

TH2: \(\left|2x-3\right|-x+1=-34\)

\(\left|2x-3\right|-x=-35\)

Với \(x\ge\frac{3}{2}\), ta có \(2x-3-x=-35\Rightarrow x=-32\)  (l)

Với \(x< \frac{3}{2}\), ta có \(3-2x-x+1=-34\Rightarrow-3x=38\Rightarrow x=\frac{38}{3}\left(l\right)\)

d) Tương tự câu c.

=>|2x+1|=|x-1|

=>2x+1=x-1 hoặc 2x+1=1-x

=>x=-2 hoặc x=0

`|2x+1|-|x-1|=0`

`<=>|2x+1|=|x-1|`

`<=>4x^2+4x+1=x^2-2x+1`

`<=>3x^2+6x=0`

`<=>3x(x+2)=0`

`<=>` $\left[\begin{matrix} x=0\\ x=-2\end{matrix}\right.$

a: \(\Leftrightarrow\left\{{}\begin{matrix}3x-2>-4\\3x-2< 4\end{matrix}\right.\Leftrightarrow-\dfrac{2}{3}< x< 2\)

c: \(\Leftrightarrow\left[{}\begin{matrix}3x-1>5\\3x-1< -5\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x>2\\x< -\dfrac{4}{3}\end{matrix}\right.\)

d: \(\Leftrightarrow\left[{}\begin{matrix}3x+1>x-2\\3x+1< -x+2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x>-3\\4x< 1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x>-\dfrac{3}{2}\\x< \dfrac{1}{4}\end{matrix}\right.\)

suy ra /2x + 1/ + /2x - 1/ lớn hơn hoặc bằng

/2x + 1 + 1 - 2x/ = /2/ = 2

Dấu bằng xãy ra khi:(2x + 1).(2x-1)

suy ra -1/2 bé hơn hoặc bằng x lớn hơn hoặc bằng 1/2

kick cho mk nhé

Chọn C.

#)Giải :

a) \(\left|x-1\right|+\left|x+2\right|=0\Leftrightarrow\orbr{\begin{cases}x-1=0\\x+2=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=1\\x=-2\end{cases}}}\)

b) \(\left|2x-1\right|+\left|y^2-y\right|=0\Leftrightarrow\orbr{\begin{cases}2x-1=0\\y^2-y=0\end{cases}\Leftrightarrow\orbr{\begin{cases}2x=1\\y^2=y\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=\frac{1}{2}\\y\in\left\{-1;0;1\right\}\end{cases}}}\)