I need help figuring out how to come up with the given answer please.

Determine the velocity of slider B in $($m$)/($s$)$ in terms of the displacement x$\_($A$),$ the

velocity of slider A$,$ and the length of the bar L$.$

Let:

x$\_($A$)=0\mathrm{.}1$m

v$=5($m$)/($s$)$

L$=3\mathrm{.}7$m

$*$

$2\mathrm{.}4$ margin of error $(+)/(-)0\mathrm{.}01$