Giúp vs :>

Cho tam giác abc. M là trung đỉêm. Chứng minh rằng ab+ac >2am

vận tốc của ca nô khi nó lại là 13 km h vận tốc dòng nước là 3 km h Tính vận tốc của ca nô khi đi xuôi dòng và ngược dòng

III. Combine each pairs of these sentences, using IF : 1. Recycle and we’ll save natural resources. ……………………………………………………….. 2. Be careful or you will fall over the rocks. ……………………………………………………….. 3. Working too much can make you feel tired. ……………………………………………………… 4. Don’t be careless or you’ll break the vase. ………………………………………………………. 5. Ha can pass the exam, she has to work hard.……………………………………………………… 6. He can do a part to save the environment by buying recycled products. ………………………………………………………………………………………………………… 7. Putting garbage into the bins is one answer to minimize pollution. ………………………………………………………………………………………………………… 8. We should take the map with us or we will lose our way on the street. ………………………………………………………………………………………………………… 9. Ellen can borrow it, but she must give it back next week. ………………………………………………………………………………………………………… 10. The authorities are thinking of raising the petrol prices. I will have to cycle to work. …………………………………………………………………………………………………………

Giúp mik với chiều nay phải nộp rồi chỉ cần làm từ 3->5

II. Put the verbs in brackets into the correct tenses. Type I 1. If the weather …………. good next weekend, we …………… away somewhere. (stay / go) 2. Come on ! If we ……………, we ………………… the bus. (hurry / catch) 3. There …………… big floods every year if the cutting down of trees continues. (be) 4. If there ……… too much litter in the streets, the environment will become polluted. (be) 5. If the sea level ………………, there will be many floods in many parts of the world. (rise) 6. They will be late for the meeting if they ………………… now. (not leave) 7. If you aren’t careful, you …………………. the plates. (drop) 8. If anyone ……………… me, please tell them I’m out. (phone) 9. If crops ………………… with pesticides, they …………… by insects in soil. (spray / destroy) 10. If he ………………. too much pesticide on vegetables, they will become edible. (not use)

21 Unless he (sell) more he won't get much commission. 22 If I lend you Ј10 when you (repay) me? 23 We'll have to move upstairs if the river (rise) any higher. 24 If he (work) hard today can he have a holiday tomorrow? 25 Ice (turn) to water if you heat it. 26 If the house (burn) down we can claim compensation. 27 If you (not like) this one I'll bring you another. 28 Unless you are more careful you (have) an accident. 29 Tell him to ring me up if you (see) him. 30 If I tell you a secret, you (promise) not to tell it to anyone else? 31 If you (not believe) what I say, ask your mother. 32 If he (like) the house will he buy it? 33 If you will kindly sit down I (make) enquiries for you. 34 Unless I have a quiet room I (not be able) to do any work. 35 She won't open the door unless she (know) who it is. 36 Should you require anything else please (ring) the bell for the attendant.

ho tam giác ABC đều cạnh a. Tính độ dài của các vectơ sau AB - AC, AB + AC

giúp mình với, mình cảm ơn nhiều ạ ❤️

I. Put the verbs in brackets into the correct tenses. Type I 1 If I see him I (give) him a lift. 2 The table will collapse if you (stand) on it. 3 If he (eat) all that he will be ill. 4 If I find your passport I (telephone) you at once. 5 The police (arrest) him if they catch him. 6 If he (read) in bad light he will ruin his eyes. 7 Someone (steal) your car if you leave it unlocked. 8 What will happen if my parachute (not open)? 9 If he (wash) my car I'll give him Ј10. 10 If she (need) a radio she can borrow mine. 11 If you (not go) away I'll send for the police. 12 I'll be very angry if he (make) any more mistakes. 13 If he (be) late we'll go without him. 14 She will be absolutely furious if she (hear) about this. 15 If you put on the kettle I (make) the tea. 16 If you give my dog a bone he (bury) it at once. 17 If we leave the car here it (not be) in anybody's way. 18 He'll be late for the train if he (not start) at once. 19 If you come late they (not let) you in. 20 If he (go) on telling lies nobody will believe a word he says.