Question by Trường Sơn Nguyễn

07/08/2017 at 13:11

Kayasari Ryuunosuke Coordinator 07/08/2017 at 13:38

a // b

=> \(\widehat{aAB\: }=\widehat{bBA}\) (2 Alternate interior angles)

Because Al and Bw are bisectors of two angles corresponding .

So \(\widehat{aAl\: }=\widehat{lAB}=\widehat{ABw}=\widehat{wBb}\)

=> \(\widehat{lAB}=\widehat{ABw}\)

But two angles are 2 Alternate interior angles

=> Al // Bw
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Trường Sơn Nguyễn 07/08/2017 at 13:27

làm ko làm nói mãi
Lê Quốc Trần Anh Coordinator 07/08/2017 at 13:24

You could go to this source for Vietnamese question: https://olm.vn/
WhySoSerious 07/08/2017 at 13:21

This is a global website and you must write in common languague : English.

All problem in Math in Vietnamese must be translate in English before posting in this website.

Please pay attention and do better next time !

Thanks :))
Trường Sơn Nguyễn 07/08/2017 at 13:14

A)Cho a+b+c=0. Tính N= a(b+c)(b^2-c^2)+b(c+a)(c^2-a^2)+c(a+b)(a^2-b^2)
B) cho a,b là hai số hữu tỉ khác 0 thỏa mãn a^5 +b^5= 2a^2b^2, chứng minh rằng 1-ab là bình phương một số hữu tỉ