I have been given this problem and cant find a solution and was wondering if anyone could help! I have looked in to matrices and artificial variables but I am unsure how to approach this problem. Any help would be AWESOMMMME. Many thanks in advance. Mal

The final optimal tableau for a maximisation Linear Programming problem with two constraints of type (<=) and two original variables, x1 and x2, is given below. The variables x3 and x4 are slack variables.

Soln x1 x2 x3 x4
x1 20 1 0 2 -1
x2 40 0 1 -1 1
z 0 0 1 1

Find the associated optimal value of the objective function, and derive the original Linear Programming problem.