Problem 1 (10 marks) Minimise: Subject to: f = 2x₁ - 6x₂ + 3x3 + 4x4 + 7x5 + 3x6 + 2x7 91 = x2 + 5x3 + 3x4 x5 +

2x6 + 3x7 ≥ 65 92 = -6x₁3x₂ − 2x3 + x4 + 2x5 - 2x6 ≥ -73 93-7x₁4x2 + 3x3 X₁, X₂ € (2,5,7,8), X3, X4 € {3,4,6} X5, X6 ≥ 0, X7 ER 4x4 + 3x5 - 2x6 x7 ≤-66