8x -7y =5 12x +13y= -8 giải pt :))

Cho hàm số y = f(x) = (m - 1)x a) Tìm m biết f(2) - f(-1) = 7 b) Cho m = 5. Tìm x biết f(3 - 2x) = 20

em đang cần gấp ạ có thể giúp em ko

Cho tam giác ABC cân tại A. Kẻ BM vuông góc AC. Kẻ CN vuông góc AB a) Chứng minh Δ ABM = Δ ACN b) Gọi K là giao điểm của BM và CN. Chứng minh AK là tia phân giác của góc A c) Gọi D là trung điểm của đoạn thẳng BC. Chứng minh 3 điểm A, K, D thẳng hàng

Cứu em với ạ em cần trước 12h30 ạ

Tìm hai số a,b bt a,b tỉ lệ thuận với 7,9và 3a —2b =30

Tìm Nghiệm của phương trình x^2+3=0

Câu 2 con người đã vận dụng kiến thức về cảm ứng ở thực vật trong trồng trọt như thế nào?

Các bạn điền các từ này vào ô trống nhé

BIRD WATCHING IN COLOMBIA Luis Morales is 18 years old and comes from a tiny village in the Andes mountains in Colombia. Until about seven years ago, one of Luis’s favourite activities was to go into the thick forest surrounding his home to hunt and kill the wildlife, especially birds. Now, however, he and a group of other local youths work with an international organisation called Wildlife World, to study and protect the birds and their environment. Wildlife World has set up several of these groups across the area. ‘Information we get from the children helps us learn how the birds and other animals use the forest, what they eat and how best we can protect them. The project has worked very well and we hope to set up more groups in the future,’ says area leader Felipe Ramos. Luis is the oldest and most experienced member of his group, having been a member since he was just 11. ‘Before I joined, I planned to leave the village as soon as I was old enough to go and find work in the city, like most young people do,’ Luis says. ‘But now I want to go to university, become a scientist and return here to carry on working to save these rare birds and their environment. Being part of the group has had a huge effect on me.’ Luis also spends time with the younger children in the village. ‘There is not much to do here after school,’ he says, ‘so I try to involve them in our activities. As well as bird watching and nature studies we also do drama and art. The drama has been particularly successful and we now have a theatre group of 30 children, which tours in the area, performing different plays.’ 82. In this text the writer is ... A. describing village life in Colombia. B. suggesting ways to help the environment. C. giving information about a project. D. advising children to join Wildlife World. 83. Seven years ago, what was Luis’s attitude towards birds in the forest? A. He wanted to learn more about them. B. He knew they were rare and in danger. C. He thought it was fun to destroy them. D. He was not interested in them at all. 84. How does Luis feel about the group? A. He is happy because he is leaving it soon. B. He is grateful because it has changed his life, C. He is miserable because he wants to stay longer. D. He is worried because he wants more young people to join. 85. According to Felipe Ramos, what is the purpose of the group? A. to find out about the behaviour of local wildlife B. to teach children how to look after the environment C. to protect children from wild animals in the forest D. to collect information about how people use the forest 86. What would Felipe Ramos say about Luis? A. Luis is a wonderful person and he knows so much about the birds and animals in this forest. He is also a really great musician. B. Luis has just joined us and is already very important to the group, mainly because he is so good with the younger children. C. I’m going to miss Luis when he goes away to study. But I am delighted that he will be back afterwards to continue his work here. D. When I first met Luis he was preparing to move to the city to find work. Luckily, I persuaded him to stay and join my group. He never wants to leave