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Cho tam giác ABC. Điểm M nằm trong tam giác AM, BM, CM kéo dài cắt BC, AC, AB tại A1, B1, C1. CMR:
a) [tex]\frac{MA1}{AA1}+\frac{MB1}{BB1}+\frac{MC}{CC1}=1[/tex]
b)[tex]\frac{MA}{AA1}+\frac{MB}{BB1}+\frac{MC}{CC1}=2[/tex]
a) [tex]\frac{MA1}{AA1}+\frac{MB1}{BB1}+\frac{MC}{CC1}=1[/tex]
b)[tex]\frac{MA}{AA1}+\frac{MB}{BB1}+\frac{MC}{CC1}=2[/tex]