cho 10 diem tren mat phang sao cho bat ky 4 diem nao cung co 3 diem thang hang chung minh dang ta co the bo di mot diem trong 10 diem da cho de 9 diem con lai cung thuot mot duong thang
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
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Nếu ta nối 1 điềm với 14 điểm còn lại thì sẽ có tất cả:15 x 14 =210 đường.
Nhưng nếu ta nối vậy thì mỗi đường sẽ lặp lại 2 lần,nên thực tế nối được:210:2=105 đường
Đ/S:105 đg
k mk nhen