[tex]A=(14,-6)\qquad B=(-4,7)\\\\\\\bold{u}=\overrightarrow{AB} =\left\ \textless \ -4-14,7-(-6)\right\ \textgreater \ =\left\ \textless \ -18,13\right\ \textgreater \ \\\\\\
||\bold{u}||=\sqrt{(-18)^2+13^2}=\sqrt{324+169}=\sqrt{493}\approx22,2[/tex]
