Answer:
Step-by-step explanation:
1. constraints with "[tex]\geq[/tex]" we should subtract surplus variable S1, S2, S3 and add artificial variable A1, A2, A3
Hence Z = 20 x1 + 32x2 + 40x3 + 0S1 + 0S2 + 0S3 + MA1 + MA2 + MA3
subject to
[tex]3x_1 +x_2+6x_3-S_1+A_1=9[/tex]
[tex]x_1+x_2-S_2+A_2=9[/tex]
[tex]4x_2+x_3-S_3+A_3=12[/tex]
and [tex]x_1,x_2,x_3,S_1,S_2,S_3,A_1,A_2,A_3\geq 0[/tex]