Join IDNLearn.com and start exploring the answers to your most pressing questions. Ask your questions and receive detailed and reliable answers from our experienced and knowledgeable community members.

Use the simplex method to solve the linear programming problem.

[tex]\[
\begin{array}{cl}
\text{Maximize} & z = 3x_1 + 2x_2 + x_3 \\
\text{subject to} & 2x_1 + 2x_2 + x_3 \leq 10 \\
& x_1 + 2x_2 + 2x_3 \leq 11 \\
& x_1 \geq 0, x_2 \geq 0, x_3 \geq 0
\end{array}
\][/tex]

Select the correct choice below and, if necessary, fill in the answer boxes to complete your choice.

A. The maximum is [tex]$\square$[/tex] when [tex]$x_1 = \square$[/tex], [tex]$x_2 = \square$[/tex], [tex]$x_3 = \square$[/tex], [tex]$s_1 = \square$[/tex], and [tex]$s_2 = \square$[/tex].

B. There is no maximum.


Sagot :

To solve the given linear programming problem using the simplex method, follow these detailed steps:

### Problem Formulation

The problem is to maximize the objective function:
[tex]\[ z = 3x_1 + 2x_2 + x_3 \][/tex]
subject to the constraints:
[tex]\[ 2x_1 + 2x_2 + x_3 \leq 10 \][/tex]
[tex]\[ x_1 + 2x_2 + 2x_3 \leq 11 \][/tex]
with non-negativity constraints:
[tex]\[ x_1 \geq 0, x_2 \geq 0, x_3 \geq 0 \][/tex]

### Step 1: Convert Inequalities to Equations with Slack Variables

To use the simplex method, we first convert the inequality constraints into equations by introducing slack variables [tex]\( s_1 \)[/tex] and [tex]\( s_2 \)[/tex]:

[tex]\[ 2x_1 + 2x_2 + x_3 + s_1 = 10 \][/tex]
[tex]\[ x_1 + 2x_2 + 2x_3 + s_2 = 11 \][/tex]

### Step 2: Initial Simplex Tableau

We set up the initial simplex tableau. The objective function can be rewritten as:
[tex]\[ z - 3x_1 - 2x_2 - x_3 = 0 \][/tex]

Our tableau looks like this:

[tex]\[ \begin{array}{c|cccccc|c} & x_1 & x_2 & x_3 & s_1 & s_2 & \text{RHS} \\ \hline s_1 & 2 & 2 & 1 & 1 & 0 & 10 \\ s_2 & 1 & 2 & 2 & 0 & 1 & 11 \\ \hline z & -3 & -2 & -1 & 0 & 0 & 0 \\ \end{array} \][/tex]

### Step 3: Perform Simplex Iterations

Let's perform the iterations:

1. Identify the entering variable: The most negative coefficient in the objective function row is [tex]\(-3\)[/tex] for [tex]\(x_1\)[/tex].

2. Identify the departing variable: Calculate the ratios of the RHS to the coefficients of [tex]\(x_1\)[/tex]:
- For [tex]\(s_1\)[/tex]: [tex]\( \frac{10}{2} = 5 \)[/tex]
- For [tex]\(s_2\)[/tex]: [tex]\( \frac{11}{1} = 11 \)[/tex]

The smallest non-negative ratio is 5, so [tex]\(s_1\)[/tex] will leave the basis, and [tex]\(x_1\)[/tex] will enter.

3. Pivot on the element [tex]\( a_{11} = 2 \)[/tex] and update the tableau.
- New row for [tex]\(x_1\)[/tex]: Divide the entire row [tex]\(s_1\)[/tex] by 2.
- Update the rest of the tableau accordingly.

After performing the required pivot operations, we eventually reach the final optimal tableau:

[tex]\[ \begin{array}{c|cccccc|c} & x_1 & x_2 & x_3 & s_1 & s_2 & \text{RHS} \\ \hline x_1 & 1 & 1 & 0.5 & 0.5 & 0 & 5 \\ s_2 & 0 & 1 & 1 & -0.5 & 1 & 6 \\ \hline z & 0 & -1 & 0.5 & 1.5 & 0 & 15 \\ \end{array} \][/tex]

### Step 4: Read off the Solution

The optimal solution from the final tableau:
- [tex]\( x_1 = 5 \)[/tex]
- [tex]\( x_2 = 0 \)[/tex]
- [tex]\( x_3 = 0 \)[/tex]

The maximum value of the objective function is:
[tex]\[ z = 15 \][/tex]

The values of the slack variables:
- [tex]\( s_1 = 0 \)[/tex]
- [tex]\( s_2 = 6 \)[/tex]

### Final Answer

A. The maximum is [tex]\( 15.0 \)[/tex] when [tex]\( x_1 = 5.0 \)[/tex], [tex]\( x_2 = 0.0 \)[/tex], [tex]\( x_3 = 0.0 \)[/tex], [tex]\( s_1 = 0.0 \)[/tex], and [tex]\( s_2 = 6.0 \)[/tex].