What is the flow conservation constraint for node $4$ of the pictured network of the transshipment problem? $($The LHS is $160,$

you just need to enter the RHS$).$

The following example shows the right form in which a potential answer should be written as:

x$\_12-$ x$\_32+8*$x$\_54$

where $x_{12}$ represents the decision variable for link $(1,2),x_{32}$ represents the decision variable for link $(3,2).$

Remember to write your expression with $*$ if you wish to show multiplication. For example, the entry in the form of $x_{12}-x_{32}$

$+8x_{-}54($with missing $*)$ is regarded as an incorrect answer.