Solve the following goal programming model by using the computer:

minimize P1d -

3 , P2d -

2 , P3d +

1 , P4d +

2 subject to 4x1 + 6x2 + d -

1 - d +

1 = 48 2x1 + x2 + d -

2 - d +

2 = 20 d +

2 + d -

3 - d +

3 = 10 x2 + d -

4 = 6 xj, d -

i , d +

i Ú 0

 LO.1