已知線性規(guī)劃問(wèn)題 
max z=x₁+2x₂+3x₃+4x₄ 
x₁ + 2x₂ + 2x₃ +3x₄≤20 
2x₁ + x₂ + 3x₃ +2x₄≤20 
x₁、x₂，x₃，x₄≥0 
其對(duì)偶問(wèn)題的最優(yōu)解為y*₁=6/5，y*₂=1/5。試用互補(bǔ)松弛定理求該線性規(guī)劃問(wèn)題的最優(yōu)解。

寫(xiě)出下列線性規(guī)劃問(wèn)題的對(duì)偶問(wèn)題 
min z=2x₁+8x₂－4x₃ 
x₁ + 3x₂－3x₃ ≥30 
－x₁ + 5x₂ + 4x₃ = 80 
4x₁ + 2x₂－4x₃≤50 
x₁≤0、x₂≥0，x₃無(wú)限制

寫(xiě)出下列線性規(guī)劃問(wèn)題的對(duì)偶問(wèn)題 
max z=2x₁+2x₂－4x₃ 
x₁ + 3x₂ + 3x₃ ≤30 
4x₁ + 2x₂ + 4x₃≤80 
x₁、x₂，x₃≥0

用兩階段法求解下述LP問(wèn)題

用大M法求解下述LP問(wèn)題