232

\overline{OA}=-2\overline{\text{i}}+\overline{\text{j}}\
\overline{OB}=\overline{OA}+\overline{AB}=2\overline{\text{i}}-\overline{\text{j}}
\ B=\left(2{,}\ -1\right)\
\overline{OC}=\overline{OA}+\overline{AB}+\overline{BC}=5\overline{\text{i}}+3\overline{\text{j}}\
C=\left(5{,}\ 3\right)