KHÔNG CẦN GIẢI RA, CHỈ CẦN NHẬN XÉT LỜI GIẢI ĐÚNG HAY SAI MỘT CÁCH TỈ MỈ LÀ ĐƯỢC!!! TỈ MỈ, RÕ RÀNG NHA, CẢM ƠN!!! đề bài: cho tam giác ABC. điểm D chia trong AB theo tỉ số 1:2, Echia trong AC theo tỉ số 2:5 DEgiao BC tại F. Tính BF:FC? GIẢI: Qua B kẻ BK //EC giao EF=K(K thuộc EF); qua B kẻ BM//EF giao AC=M(M thuộc AC). vì tam giác ECF có BM//EF=> FB/FC=EM/EC (theo định lý Ta lét) vì tam giác EFC có BK//EF( giả thiết) =>> FK/EF=FB/FC=KB/EC(hệ quả định lý Ta lét) Vì điểm D chia trong AB theo tỉ số 1:2=>AD/DB=1/2=>AD/AB=AD/(DB+AD)=1/(1+2)=1/3 vì điểm E chia trong AC theo tỉ số 2:5=>AE/EC=2/5=>AE/AC=AE/(EC+AE)=2/(5+2)=2/7 vì tam giác ABM có DE//BM(BM//EF mà D lại thuộc EF) => AD/BD=AE/EM=>>AE/EM=1/2=>FM=2AE (1) vì AE/EC=2/5(giả thiết)=>EC=5AE/2 (2) từ (1) và(2)=> EM/EC=2AE/5AE/2=4/5 vì FB/FC=EM/EC(chứng minh trên)=> FB/FC=4/5

I / Choose the best option A,B,C, or D to complete each of the following sentences(Chọn câu đúng): 1/I’m going away……..........a few days. a.since b.in c.for d.during 2/My friend suggested ......................….by car. a.togo b.go c.going d.goes 3/Cool and burns immediately so as to… tissue damage. a.ease b.relieve c.minimize d.maximize 4/The lane is…... …Nguyen Trai street and Tran Hung Dao street. a.near b.between c.beside d.on 5/.I ..... on a farm when I was a young girl. a.use to living b.use to live c.used to live d.used to living 6/Would you mind………... .the windows. a.to close b.closing c.close d.closed 7/There are flights daily to Ho Chi Minh city…… Monday. a.besides b.after c.except d.on 8/My friend suggested............... ..by car. a.togo b.go c.going d.goes 9/Na………me wave to her. She………… …....in the other direction. a.see/is looking b.didn’t see/was looking c.was seeing/looked d.doesn’t see/looks 10/It’s ….to travel around Vietnam. a.interesting b.interested c.interestingly d.interestedly 11/……… ....you mind if I smoke? a.could b.don’t c.do d.would 12/Milk…… …to the houses by the milkman everyday. a.bring b.is bring c.is brought d.has brought 13/Milk bottles can be…… after being cleaned. a.recycled b.thrown away c.broken d.reused 14/I take part……. most youth activitives of my school. a.of b.on c.to d.in 15/This project…… .next month. a.is carried out b.will carried out c.carries out d.will be carried out 16/There are flights daily to Ho Chi Minh city.......... Monday. a.besides b.after c.except d.on 17/We were looking forward to….you in June. a.seeing b. see c.saw d.be seen 2.His parents are always proud..... ....him . a.about b.of c. on d.with 18/I will come and……… ..at 7 o’clock. a.pick up you b.pick you up c.see up you d.see you up 19/Today I went on …… .tour around Asia. a. a eight hours b.a eight hour c.an eight hours d.an eight hour 20/The teacher…… .a class at eight o’clock yesterday evening. a.is having b.was having c.has d.has had 21/…… ..I was having dinner,my husband was watching TV. a.While b.If c.Because d.As 22/Yesterday Lan went to the market and… some food. a.buy b.have bought c.buyed d.bought 23/Cool and burns immediately so as to....... tissue damage. a.ease b.relieve c.maximize d.minimize 24/How do you ……… ….about the people living here? a.fell b.fall c.feel d.felt 25/How many………………………………......................……… in the last competition? a.activities were there b.activities there were c.activities are there d.activities there are 26/How were the activitives……… .? a.organized b.made c.put d.done 27/The cupboard is open and everything.. a.is broken b.was broken c.has been broken d.would be broken 28/Is Ha Long Bay a… ..Heritage? a.World Natural b.Natural World c.World Cutural d.Cutural World 29/She has...... ...over 30 pages since yesterday. a.writen b.wrote c.written d. write

cho tam giác ABC ,trên AB lấy điểm M sao AM = 1/3 AB.Trên AC lấy N sao cho AN= 2/3 AC.Biết diện tích tam giác ABC là 90 cm vuông.Tính s tứ giác MNCB Giúp Mk, Mình cho hay nhất

GIẢI GIÚP EM TÍ EM ĐI HỌC Ạ :33

Cho tam giác ABC vuông ở B, AB= 8 cm, BC = 6 cm. Gọi D là điểm đối xứng của B qua AC. a) CMR : bốn điểm A, B, C, D cùng thuộc một đường tròn. b) Tính bán kính đường tròn nói trong câu a.

vẽ anime nam (tradi/digi) y/c: full line màu tuỳ chụp rõ (digi chụp layer) kí cuối cùng là đẹp trai :))))

Phân ra cột: Introducing the ideas/ Explaining/ Concluding

2.1. Mức độ nhận biết 1. Let’s to go abroad for our summer vacation this year A B C D 2. I suggest to use banana leavesto wrap food. A B C D 3. Why don,t we used buses instead of motorbikes to avoid traffic jams. A B C D 4. How aboutreduced the amount of garbage we produce ? A B C D 5. Ithink that we should turned off the faucet . A B C D 6. The principal wants us pay more attention to our study. A B C D 7. Students stoppedto make noise when the teacher came in. A B C D 8. Would you mindto turning off the radio? A B C D 9. My parents decided take a taxi because it was too late. A B C D 10. All of us are very fond of read books after school. A B C D 11. They don’t like go to the zoo because they hate animals. A B C D 12. My told me signing a paper admittig his guilt. A B C D 13. The children are strong enoughcarry that heavy bag from the park to their house. A B C D 14. Could you to help me open this door? A B C D 15. The teacher asked us writing the exercises carefully. A B C D 16. He is interested in playsports. A B C D 17. You will be abledoing it yourself when you are older. A B C D 18. Some students avoid to look at the teacher if they don’t want to answer a question A B C D 19. She prefersdoing homework tohang out with friends. A B C D 20. Finally, they finishedto complete their tests. A B C D

Vẽ chibi cute đi nào mn ơi Ngoài lề: Ước gì tui đc ngồi cạnh 1 đứa như này....

người ta điều chế kẽm oxit = cách đốt kẽm trong oxi. a) tính thể tích oxi (đktc) cần thiết để điều chế 40,5g kẽm oxit. b) muốn có lg oxi nói trên cần phân huỷ bnh gam kali clorat (KClO3). giả thiết các pứ có hiệu suất 100%