Most students would like to the English Club. They want to improve their English.
在△ABC中,E,F分别为AB,AC中点,P为EF上任意一点,实数x,y满足PA→+xPB→+yPC→=0→,设△ABC,△PCA,△PAB的面积分别为S,S2,S3,记S1S=λ1,S2S=λ2,则λ1,λ2取得最大值时,2x+3y的值为( )