\(A=\dfrac{n-3}{n+2}=1-\dfrac{5}{n+2}\)

TH1 : n >=-1 => n+2>=1 >0

\(\Rightarrow A\ge1-\dfrac{5}{1}=-4\)

Dấu = khi n=-1

TH2: n<= -3 => n+2<=-1 <0 

\(\Rightarrow A\le1-\dfrac{5}{-1}=6\)

Dấu = xảy ra khi n=-3

Cảm ơn vì bn đã giúp. Nhưng bn có thể giải chi tiết cho mik đc ko ạ? 

\(\Leftrightarrow x\in\varnothing\)

em cảm ơn ạ

C

1 cooking 

2 listening

3 reading

4 playing

5 cycling

1 People collect a lot of things such as stamps, milk bottle labels, comic books as well as car toys

2 She is 20 years old

3 She is a hairdresser

4 It is collecting candy shells

5 Her friends and relatives

B

1 F

2 F

3 F

4 F

5 T

GTNN là gì vậy??

\(B=\left|2x+3,5\right|+\left|2x+\frac{7}{2}\right|\)

\(=\left|3,5-2x\right|+\left|2x+3,5\right|\ge\left|3,5-2x+2x+3,5\right|=7\)

Dấu '' = '' xảy ra khi \(\left(3,5-2x\right)\left(2x+3,5\right)\ge0\)

\(\Rightarrow\orbr{\begin{cases}3,5-2x\ge0;2x+3,5\ge0\\3,5-2x\le0;2x+3,5\le0\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}2x\le3,5;2x\ge-3,5\\2x\ge3,5;2x\le-3,5\end{cases}}\)

\(\Rightarrow\orbr{\begin{cases}x\le1,75;x\ge-1,75\Rightarrow-1,75\le x\le1,75\\x\ge1,75;x\le-1,75\text{(Vô lý)}\end{cases}}\)

Vậy \(MinB=7\Leftrightarrow-1,75\le x\le1,75\)