transportation costing

any one can answer when we solve transporatation problem we have a dummy column/row and also its a maximization so while converting into minimization should we substract the highest element from dummy column/row also or keep the zeros as it is.

how to determine whether to keep dummy as it is or substract from it ?

as i have solved questions it shows that it can be done in both ways

please help but while solving u get different answers

is there a way to solve it or any method will do?