xét từng câu ta có:

câu a sai vì n thuộc số thực thì (x/y)ⁿ=xⁿ/yⁿ

C,D thì sai nốt

vậy chọn câu B

câu a nha

94,24 nha bạn

2356 : [12 + 2 : 2 . (24 : 2 + 23) + 3 . 12] . 2

= 2356 : [12 + 2 : 2 . 35 + 3 ] . 2 

= 2356 : [ 12 + 35 + 3 ] . 2 

= 2356 :  50 . 2 

= 47,12 . 2 

= 94,24

nha bạn 

bán 30 đôi đầu tiên lãi số tiền là : 

( 200000 : 100 x 140 ) x 30 = 8400000 ( đồng ) 

bán số giày còn lại lãi số tiền là : 

( 200000   : 100 x 130 ) x 20 = 5200000 ( đồng )

cửa hàng lãi số tiền là : 

( 200000 x 50 ) - ( 8400000 + 5200000 ) = 3600000 ( đồng )

Do you want to be fitter and healthier? Would you to look younger? Do you want to feel (1) ....more.... relaxed?Then try a (2) ....few....days at a health farm. Health farms are becoming (3) ....one.... of the most popular places (4) ....for.... a short break. I went to Henley Manor for a weekend. It's (5)....the....largest health farm in the country (6) ....but.... it isn't the most expensive.After two days of exercise I (7) ....feel....10 times better. But the best thing for me was the food. It was all very healthy of (8)....course....,but it was excellent,too.
If you are looking for something a (9)....little.... cheaper, try a winter break. Winter is the darkest and the coldest (10) ....season.... of the year,and it can also be the worst time for your body. We all eat too (11) ....much.... and we (12) ....don't.... take enough exercise. A lot of health farms offer lower prices from Monday (13)....to....Friday, from November to March.

1. more

2. one

3. for

4. the

5. but

6. feel

7. course

8. little

9. season

10. much

hik vẽ đâu

hic k cop đc hình ạ :(

55. I'm looking for accommodation to stay.

56. 1. Travel agency

2. Traveller's cheques 

3. Check-in desk 

4. Boarding card 

5.  Departure lounge 

6. Seat belt 

7. Take off

8. Excess baggage 

9. Passport control

10. Duty – fee

11. Suitcase 

12. Charter flight 

13. Runway  

14.  Holiday resort

a, TH1 : \(\hept{\begin{cases}x-\frac{1}{3}>0\\x+\frac{2}{5}>0\end{cases}\Leftrightarrow\hept{\begin{cases}x>\frac{1}{3}\\x>-\frac{2}{5}\end{cases}\Leftrightarrow}x>\frac{1}{3}}\)

TH2 : \(\hept{\begin{cases}x-\frac{1}{3}< 0\\x+\frac{2}{5}< 0\end{cases}}\Leftrightarrow\hept{\begin{cases}x< \frac{1}{3}\\x< -\frac{2}{5}\end{cases}\Leftrightarrow x< -\frac{2}{5}}\)

Vậy x > 1/3 ; x < -2/5 

b, Vì \(x+1>x+\frac{3}{5}\)

nên \(\hept{\begin{cases}x+1>0\\x+\frac{3}{5}< 0\end{cases}\Leftrightarrow\hept{\begin{cases}x>-1\\x< -\frac{3}{5}\end{cases}\Leftrightarrow-1< x< -\frac{3}{5}}}\)

\(\left(x-\frac{1}{3}\right)\left(x+\frac{2}{5}\right)>0\)

\(\orbr{\begin{cases}x>\frac{1}{3}\\x< -\frac{2}{5}\end{cases}}\)

<cùng dương, cùng âm>

\(A=\left|x-2002\right|+\left|x-2003\right|=\left|x-2002\right|+\left|2003-x\right|\ge\left|-2002+2003\right|=1\)

Dấu ''='' xảy ra khi \(\left(x-2002\right)\left(2003-x\right)\ge0\Leftrightarrow2002\le x\le2003\)

Vậy GTNN của A bằng 1 tại 2002 =< x =< 2003 

\(B=5,5-\left|2x-5\right|\le5,5\)

Dấu ''='' xảy ra khi x = 5/2

Vậy GTLN của B bằng 5,5 tại x = 5/2