A mathematical model was created and solved using linear programming. The optimal values were determined: x1 = 10 and x2 = 10. If one of the constraints is: 4x1 + 2x2 >= 55, you can conclude that:

there are 15 units of slac

there are 5 units of surplu

there are 15 units of surplus this is a binding constraint, so there is no slack or surplus

there are 5 units of slack