so duong thang tao thanh tu 10 diem phan biet trong do khong co 3 diem nao thang hang

so duong thang duoc tao thanh tu 10 diem trong do co 3 diem thang hang la

Cho truoc mot so duong thang phan biet khong co 3 diem nao thang hang. So duong thang tao thanh tu cac diem do la 36, tinh so diem ?

1. Tren 1 duong thang xy lay 4 diem phan biet A,B,C,D hay chi ra cac tia doi nhau 

2. cho 10 diem trong do khong co ba diem thang hang . Cu qua hai diem ta ve duoc 1 duong thang . Hoi co tat ca bao nhieu duong thang?

3. cho n diem trong do khong co ba diem nao thang hang . Cu qua hai diem trong so cac diem do ve duoc 1 duong thang. Biet rang co 435 duong thang tao thanh .Tim n?

cho 1000 diem phan biet trong do co dung 3 diem thang hang hoi co bao nhieu duong thang tao thanh boi 2 trong 1000 diem do

cho 50 diem trong do co dung m diem thang hang , ngoai ra ko co 3 diem naop thang hang. cu qua 2 diem ta ve duoc 1 duong thang .so duong thang ve duoc la 1215 duong thang.tim m

cho 20 diem phan biet , trong do co dung 7 diem thang hang , ngoai ra khong co 3 diem nao thang hang.cu qua 2 diem ta ve duoc 1 duong thang.hoi tu 20 diem do ta ve duoc bao nhieu duong thang

So duong thang tao thanh  từ 5 diem phan biet trong do khong co 3 diem nao thang hang la bao nhiêu?

cho 20 diem phan biet trong do co dung 7 diem thang hang ngoai ra khong co ba diem thang  hang cu qua hai diem ta ve duoc mot duong thang hoi tu  20 diem do ve duoc tat ca bao ngieu duong thang

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