OA = ([tex] x_{O}[/tex] - [tex] x_{A} [/tex])i +[tex]( y_{0} - y_{A}) [/tex]j
= -2i + j =>3*OA = 3(-2i + j) = -6i + 3j
OB = [tex]( x_{O} - x_{B})i + ( y_{O} - y_{B})[/tex]j
= i -2j => 2*OB = 2(i - 2j) = 2i - 4j
3*OA + 2*OB = -6i + 3j +2i - 4j = -4i -j = -1(4i + j)