thang MB theo ti sd ndo ? 5 chia doan thang MA theo ti sd ndo ?' d) Chiing minh rdng : Ne'u dilm M chia doan thang AB theo ti sd ^ ^t 1 thivdi dilm O bdt ki, ta ludn cdOA-kOB17. Cho
tam giac ABC. Goi M, N, P ldn luot la cdc dilm chia cdc doan thangAB, BC, CA theo ciing ti sd ^ 9^ 1. Chiing mi[r]