Explanation
any vector in the plane can be writen as a linear combination of the 2 standar unit vectors
[tex]\begin{gathered} i=\langle1,0\rangle\text{ j=}\langle0,1\rangle \\ as\text{ follows} \\ V=\langle a,b\rangle=a\langle1,0\rangle+b\langle0,1\rangle=ai+bj \end{gathered}[/tex]hence
Step 1
component form
[tex]\begin{gathered} U=\text{ terminal point -initial point} \\ U=(9-(-7),(-3-1)=\langle16,-4\rangle \end{gathered}[/tex]now, as a linear combination
[tex]U=16i-4j[/tex]I hope this helps you