6.在ΔABC\Delta ABCΔABC中,DDD为ACACAC中点,连接BDBDBD,若BE→=2ED→,AE→=xAB→+yAC→\overrightarrow{BE}=2\overrightarrow{ED},\overrightarrow{AE}=x\overrightarrow{AB}+y\overrightarrow{AC}BE=2ED,AE=xAB+yAC,则x+yx+yx+y的值为((( )))