过E作EG//BC交AD于G
易证△AEG~△ABD
所以,EG/BD=AE/AB=1/(1+3)=1/4
易证△EFG~△CFD
所以,EF/FC=EG/DC=EG/(BD/2)=2EG/BD=2*1/4=1/2
过D作DH//AB交CE于H
仿上述方法,得BE/DH=CB/CD=1/3
AF/FD=AE/DH=(BE/3)/DH=BE/3DH=3*1/3=1
所以,EF/FC + AF/FD=1/2+1=3/2