Solutions of the given linear programming problem

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Discussion Overview

The discussion revolves around a linear programming problem involving the minimization of a function subject to certain inequalities. Participants explore the application of the simplex method and the Two-Phase method to find solutions, while also discussing the nature of the solutions and their validity.

Discussion Character

  • Technical explanation
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • One participant presents a linear programming problem and claims to find infinite solutions of the form $(x,y,z,w)=(1-m, 2+0.4m, 0, 0.2m)$ with a minimum value of 8.
  • Another participant agrees with the first claim, providing reasoning based on the addition of the inequalities leading to a derived inequality that suggests the solutions are valid when $z=0$.
  • A later reply acknowledges the previous contributions but expresses a sense of being overtaken in the discussion, indicating a dynamic exchange of ideas.

Areas of Agreement / Disagreement

Participants generally agree on the validity of the proposed solutions, but the discussion includes multiple contributions that reflect a collaborative exploration rather than a definitive conclusion.

Contextual Notes

There are no explicit limitations noted, but the discussion relies on the assumptions made in the derivation of the solutions and the application of the simplex method.

mathmari
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Hello! :o
Given the following linear programming problem
$$\min(2x + 3y + 6z + 4w)$$
$$x+2y+3z+w \geq 5$$
$$x+y+2z+3w \geq 3$$
$$x,y,z,w \geq 0$$
I am asked to find all the solutions using the simplex method.

To solve this problem we use the Two-Phase method, don't we?
Then I found that there are infinite many solutions, $(x,y,z,w)=(1-m, 2+0.4m, 0, 0.2m), 0≤m≤1$ with $min=8$.
Could you tell me if this is right?
 
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mathmari said:
Hello! :o
Given the following linear programming problem
$$\min(2x + 3y + 6z + 4w)$$
$$x+2y+3z+w \geq 5$$
$$x+y+2z+3w \geq 3$$
$$x,y,z,w \geq 0$$
I am asked to find all the solutions using the simplex method.

To solve this problem we use the Two-Phase method, don't we?
Then I found that there are infinite many solutions, $(x,y,z,w)=(1-m, 2+0.4m, 0, 0.2m), 0≤m≤1$ with $min=8$.
Could you tell me if this is right?
Your answer is certainly correct, because if you add the two inequalities you get $2x + 3y + 5z + 4w \geqslant 5+3=8$. Therefore $2x + 3y + 6z + 4w \geqslant 8+z$, which is minimised by taking $z=0$. Your solutions, with $z=0$, clearly satisfy all the given conditions, so they must be right.
 
mathmari said:
Hello! :o
Given the following linear programming problem
$$\min(2x + 3y + 6z + 4w)$$
$$x+2y+3z+w \geq 5$$
$$x+y+2z+3w \geq 3$$
$$x,y,z,w \geq 0$$
I am asked to find all the solutions using the simplex method.

To solve this problem we use the Two-Phase method, don't we?
Then I found that there are infinite many solutions, $(x,y,z,w)=(1-m, 2+0.4m, 0, 0.2m), 0≤m≤1$ with $min=8$.
Could you tell me if this is right?

Looks good! ;)

EDIT: Aargh, overtaken by Opalg.
 
Opalg said:
Your answer is certainly correct, because if you add the two inequalities you get $2x + 3y + 5z + 4w \geqslant 5+3=8$. Therefore $2x + 3y + 6z + 4w \geqslant 8+z$, which is minimised by taking $z=0$. Your solutions, with $z=0$, clearly satisfy all the given conditions, so they must be right.

Great! Thank you for your answer! :o

- - - Updated - - -

I like Serena said:
Looks good! ;)

EDIT: Aargh, overtaken by Opalg.

Nice! Thank you! :o
 

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