Answer
$(3,1)$
Work Step by Step
$A(-2,1),B(1,2)$
Vector AB is the vector from A to B, find it by subtracting the corresponding components of A from B.
$a=AB=\lt1-(-2),2-1 \gt =\lt 3,1\gt $
The equivalent representation starting at the origin is a vector from point $(0,0)$ to the point $(3,1)$.