证明:
过点B作BG∥AC交直线ED于G
∵BG∥AC
∴△FBG∽△FCD ,△GBE∽△ADE
∴CF:BF=CD:BG AE:EB=AD:BG
∵D是AC中点∴AD=DC
∴CD:BG=AD:BG
∴CF:BF=AE:EB
证毕
证明:作CG//BA,交EF于G则∠A=∠DCG,∠AED=∠CGD又∵AD=CD∴⊿AED≌⊿CGD(AAS)∴AE=CG∵CG//BA∴⊿FGC∽⊿FEB∴CG/EB=CF/BF∴AE/EB=CF/BF