文[1]通过构造具有相同起点的两个向量之差,来进行解答三道历年高考数学题目,方法虽妙,但过程有些复杂,并不易为多数同学掌握.笔者品读后,尝试构造两个向量之和,发觉效果更好些,为便于同学们掌握,对文[1]中三题进行解答如下:例1(2008年全国卷一3)在△ABC中,△→AB=c,→AC=b.若点D满足→BD=2→DC,则→AD=().(A)23b+13c(B)53c-23b(C)23b-13c(D)13b+23c解析∵→BC=→BA+→AC=-→AB+→AC=-c+b, Wen [1] by constructing the difference between the two vectors with the same starting point to answer math problems in three years college entrance examination, the method is wonderful, but the process is somewhat complicated and not easy for most students to master the author after reading, try to construct two In order to facilitate students to master, the following three questions are answered in [1]: Example 1 (National Volume 1 of 2008) In △ ABC, △ → AB = c, → AC = b. If the point D satisfies → BD = 2 → DC, then → AD = () A 23b + 13c 53c-23b 23b-13c (D) 13b + → BA + → AC = - → AB + → AC = -c + b,