Cho pt x²+(2m-1)x-m=0.Tìm m để pt có nghiệm:

a,Tìm giá trị nhỏ nhất của A=x₁²+x₂²-5x₁x₂.

Help!!!

Cho pt x²+(2m-1)x-m=0.Tìm m để pt có nghiệm:

a,Tìm giá trị nhỏ nhất của A=x₁²+x₂²-5x₁x₂.

Help!!!

Cho tam giác ABC nhọn , nội tiếp đường tròn (O) bán kính R , ba đường cao AD , BE , CK của tam giác ABC cắt nhau tại H sao cho AH = R , gọi M , N lần lượt là trung điểm của AB , AC  

a ) C/m AMON là tứ giác nội tiếp

b) Tính diện tích hình tròn ngoại tiếp tứ giác AMON 

c)  Tính số đo góc BAC

Chỉ cần vẽ thôi cũng đc!!!!!!!

cho đường tròn (O) ,từ điểm A nằm ngoài đường tròn kẻ hai tiếp tuyến AB và AC (B,C là hai tiếp điểm).Gọi M là giao điểm OA và BC,D là một điểm nằm trên đường tròn (O) sao cho D không nằm trên đường thẳng OA,kẻ dây cung DE đi qua M.CMR:Tứ giác ADOE nội tiếp.

Cho điểm M thuộc nửa đường tròn có đường kính AB (M khác A và B). Ta lấy điểm I nằm giữa M và B, kẻ IH vuông góc với cạnh AB tại H. Đoạn thẳng AI cắt đoạn thẳng MH tại điểm K. Chứng minh rằng 

Mr Lam/now wear/face mask/protect/him/Covid 19.

Nowadays people are more aware that wildlife all over the world is in danger. Many species of animals are threatened, and could easily become extinct if we do not make an effort to protect them. There are many reasons for this. In some cases, animals are hunted for their fur or other valuable parts of their bodies. Some birds, such as parrots, are caught alive, and sold as pets. For many animals and birds, the problem is that their habitat - the place where they live - is disappearing. More land is used for farms, for houses and industry, there are fewer open spaces than there once were. Farmers use powerful chemicals to help them grow better crops, but these chemicals pollute the environment and harm the wildlife. The most successful animals on earth – human beings – will soon be the only ones left, unless we can solve this problem.

1.What is happening to the wild animals?

A.They are in danger.

B.They beecome expensive.

C.More people love them.

D.They die.

2.According to the passage,one of the reasons that people hunt animals is__________.

A.People want to take them to the zoo.

B.They want to kill them.

C.they want to sell them as pets

D.they went their fur or other valuable parts of their boies

3.What does the word 'they' in line 5 refer to?

A.parrots

B.birds

C.animals and birds

D.elephants

4.What is the disadvantage of using more land for farm?

A.People will have more food

B.People will build more houses and industry zones

C.Animals and birds will not have a "house" to live in

D.People are happy with this

5.What can be the tile of the passage?

A.Birds are in danger!

B.The threat to the Environment

C.The most Successful Animals

D.Land pollution

Nowadays people are more aware that wildlife all over the world is in danger. Many species of animals are threatened, and could easily become extinct if we do not make an effort to protect them. There are many reasons for this. In some cases, animals are hunted for their fur or other valuable parts of their bodies. Some birds, such as parrots, are caught alive, and sold as pets. For many animals and birds, the problem is that their habitat - the place where they live - is disappearing. More land is used for farms, for houses and industry, there are fewer open spaces than there once were. Farmers use powerful chemicals to help them grow better crops, but these chemicals pollute the environment and harm the wildlife. The most successful animals on earth – human beings – will soon be the only ones left, unless we can solve this problem.

1.What is happening to the wild animals?

2.According to the passage,one of the reasons that people hunt animals is__________.

3.What does the word 'they' in line 5 refer to?

4.What is the disadvantage of using more land for farm?

5.What can be the tile of the passage?