alo các anh chị ơi hic hic giúp em

Bài 1. Cho tam giác ABC vuông ở A, đường cao AH. a) Biết AH = 6cm, BH = 4,5cm, tính AB, AC, BC, HC. b) Biết AB = 6cm, BH = 3cm, tính AH, AC, CH

Cho tam giác ABC,2 trung tuyến BM,CN cắt nhau tại G.Gọi E,F lần luọt là trung điểm của GB và GC. a, Chứng minh MNEF là hình bình hành b, Lấy I,J thuộc tia đối của MG và NG sao cho MI=MG và NI=NG.Chứng minh tứ giác BCIJ là hình bình hành

Write a paragraph supporting the idea that secondary school students should go to school all day Secondary school students should go to school all day.

Giải nhanh giúp em với ạ c1 đến c3 ạ

9 , $\dfrac{\sqrt[]{-3x}}{x^{2}-1}$ 10 , $\sqrt[]{(x+2)(x-3)}$ 11, $\sqrt[]{(2x+1)(x-2)}$ 12 , $\sqrt[]{(x+3)(3-x)}$ 13 , $\sqrt[]{x-2}+$ $\dfrac{1}{\sqrt[]{x-2}}$

giúp mk nhanh với hơi ít điểm nhó, kẻm ơn mng. Nếu cacban thấy ít đ qá thì nói mk nhó

Travelling is a good hobby. If you have very little money, backpacking is a good way to travel. Many students like to backpack. They can travel cheaply. They can travel to many places. These travelers carry their belongings in large backpacks. They are called backpackers. Backpackers take buses or trains to save money. They camp outdoors to sleep. If they stay in a city, they may go to a hostel. Hostels are very cheap. Travelers often share rooms at hostels. There are only a few toilets and baths. People share them, too. Hostels are good places to meet each other travelers. You can make friends. They can tell you about fun things to do in the area. Many hostels have kitchens. These kitchens have stoves. Some have toasters. You can buy your food from a store. Then, you can cook at the hostel. This is cheaper than eating out. Just remember to clean up when you are done! 20. What kind of travel will people choose if they have very little money? A. Backpacking B. Adventure travel C. Family travel 21. What kind of transportation do backpackers choose? A. Buses B. Trains C. Buses or trains. 22. What does the word “hostel” in line 4 refer to? A. homestay B. inn C. apartment 23. Can backpackers cook at the hostel? A. Yes, they can. B. No, they can’t. C. They can cook some simple dishes 25. What is the best title for the passage? A. Drawback of backpacking. B. A good way to travel. C. Benefits of travelling

Làm một bài văn liên hệ trách nhiệm bản thân trong xây dựng nền quốc phòng toàn dân hiện đại? ( Hơn 300 chữ)

tìm giá trị lớn nhất: 10x-x^2-2 2x-2x^2+3