Ta có:

\(x^{10}-\left(100+1\right)x^9+\left(100+1\right)x^8-\left(100+1\right)x^7+.....-\left(100+1\right)x+100+1\)

\(=x^{10}-100x^9-x^9+100x^8+x^8-100x^7-x^7+......-100x-x+100+1\)

đẹp wá

Ta có:\(C=2\left(x-y\right)+13x^3y^2\left(x-y\right)+15xy\left(y-x\right)+1\)Thế \(x-y=0\) vào C ta được:

\(C=0+0+0+1\)

C = 0

1.This film begins (this film/ begin) at 3.30 or 4.30.

2. The art exhibition opens (open) on 3 May and ends (end) on 15 July

3. The train leaves (leave) Plymouth at 11.30 and arrives (arrive) in London at 14.45

4. We starts (start) out work on Monday and finishs (finish) on Friday

5. I'm bored with this TV program.When does it finish ? (it/ finish)

6. "What time does your train leave (your train/leave) tomorow?"

" 7 o'clock in the morning, it gets (get) into Paris at 11

7. Next Friday is (be) thirteenth

8." Where do they collect ( they/collect) garbage?" at Dong Xuan market"

9. " What time do you finish (you/ finish) your work tomorrow?

10. My train leaves (leave)at 11.30, so I need to be (be) at the station by 11.15

1. David (repair) repaired the TV set last night.

2. I don't know what I (do) will do when I leave my home town.

3. I (wait) will wait until he writes his next novel.

4. He (do) did yesterday's homework.

5. Parents want their children (learn) to learn - hard.

6. This film is really sad. I think I (cry) will cry soon.

tick luon nhe

Gọi x (phút) là thời gian người đó đi từ A đến B.

Trong x phút , người đó gặp \(\dfrac{x}{15}\) chuyến xe buýt đi từ A đến B đồng thời gặp \(\dfrac{x}{10}\) chuyến xe buýt đi từ B đến A.

Nếu khi đến B ,người đó đi về A thì trong x phút người đó gặp \(\dfrac{x}{15}\) chuyến xe đi từ B về A đồng thời \(\dfrac{x}{10}\) phút đi từ A về B.

Vậy trong vòng 2x (phút) người đó gặp :

\(\dfrac{x}{15}+\dfrac{x}{10}=\dfrac{x}{6}\) (chuyến) xe buýt đi từ B về A.

Thời gian các xe rời bến là sau :

\(2x:\dfrac{x}{6}=12\) (phút)

Ray : Hi ,my name ' s Ray

Rou :Hi,Ray.My name ' s Rou

Ray : How are you ?

Rou : Good , thank you. And you ?

Ray : I'm fine

Rou : Oh! I'm Rio.

Rio : Hi

Rou :Bye,Ray. See you again

Ray :Bye

1) Her father works on the farm

2) He has breakfast and goes to school.

3) How many pens on the desk ?

4) We have history and math on Monday.

5)He is reading the interesting book.