maximize 2x1-3x2+3x2 subject to x1+3 x2 =7 x1-2x2 2x5 ≤4 X1:X2.X2 ≥ 0. maximize 2x1- 3x2+3x subject to x1+x2 x ≤7 x1+x2 x2 ≥7 x1-2x2 2x3 ≤ 4 X1.x2.x2 乙 0 maximize Cx maximize 2x1-3x2 +3x3 subject to subject to x1+x2 x3≤ 7 + Ax ≤ -x1-x2 X3 b ≤-7 x1-2x2 +2x3 4 ≥ 0 X1,X2,X3 ≥ 0