OA=a+b,OB=2a-b,则:
a=(1/3)(OA+OB),b=(2/3)OA-(1/3)OB
1、OC=OA+(2/3)AB=OA+(2/3)(OB-OA),代入即可;
2、OC=OB+BC=OB+(3/2)BA=OB+(3/2)(OA-OB),代入计算即可.
OA=a+b,OB=2a-b,则:
a=(1/3)(OA+OB),b=(2/3)OA-(1/3)OB
1、OC=OA+(2/3)AB=OA+(2/3)(OB-OA),代入即可;
2、OC=OB+BC=OB+(3/2)BA=OB+(3/2)(OA-OB),代入计算即可.