Use the method of this section to solve the linear programming problem:

[tex]\[
\begin{array}{ll}
\text{Minimize} & C = x + 2y \\
\text{subject to} & 4x + 7y \leq 48 \\
& 2x + y = 22 \\
& x \geq 0, \; y \geq 0
\end{array}
\][/tex]



Answer :

To solve the given linear programming problem using the method of linear programming, we need to follow these steps:

1. Formulate the Objective Function:
The goal is to minimize the objective function [tex]\( C = x + 2y \)[/tex].

2. Identify the Constraints:
The problem includes the following constraints:
[tex]\[ \begin{cases} 4x + 7y \leq 48 \\ 2x + y = 22 \\ x \geq 0 \\ y \geq 0 \end{cases} \][/tex]

3. Graphical Representation:
Since the problem involves two variables, we can visualize the constraints graphically to understand the feasible region.

- Plot the inequality [tex]\( 4x + 7y \leq 48 \)[/tex].
- Plot the equality [tex]\( 2x + y = 22 \)[/tex].

The feasible region is where all constraints overlap in the first quadrant because [tex]\( x \geq 0 \)[/tex] and [tex]\( y \geq 0 \)[/tex].

4. Find the Intersection Points:
To locate the optimal point, we need to find the intersection points of the constraints.

- Solve the system of equations [tex]\( 2x + y = 22 \)[/tex] and [tex]\( 4x + 7y = 48 \)[/tex].

From [tex]\( 2x + y = 22 \)[/tex]:
[tex]\[ y = 22 - 2x \][/tex]

Substitute [tex]\( y = 22 - 2x \)[/tex] into [tex]\( 4x + 7y = 48 \)[/tex]:
[tex]\[ 4x + 7(22 - 2x) = 48 \][/tex]
[tex]\[ 4x + 154 - 14x = 48 \][/tex]
[tex]\[ -10x + 154 = 48 \][/tex]
[tex]\[ -10x = 48 - 154 \][/tex]
[tex]\[ -10x = -106 \][/tex]
[tex]\[ x = 10.6 \][/tex]

Substitute [tex]\( x = 10.6 \)[/tex] back into [tex]\( y = 22 - 2x \)[/tex]:
[tex]\[ y = 22 - 2(10.6) \][/tex]
[tex]\[ y = 22 - 21.2 \][/tex]
[tex]\[ y = 0.8 \][/tex]

5. Evaluate the Objective Function:
Substitute the coordinates [tex]\( (10.6, 0.8) \)[/tex] into the objective function [tex]\( C = x + 2y \)[/tex]:
[tex]\[ C = 10.6 + 2(0.8) \][/tex]
[tex]\[ C = 10.6 + 1.6 \][/tex]
[tex]\[ C = 12.2 \][/tex]

Therefore, the minimum value of the objective function [tex]\( C \)[/tex] is [tex]\( 12.2 \)[/tex], which occurs at [tex]\( x = 10.6 \)[/tex] and [tex]\( y = 0.8 \)[/tex].

To summarize:
- The optimal solution is [tex]\( x = 10.6 \)[/tex] and [tex]\( y = 0.8 \)[/tex].
- The minimum value of the objective function [tex]\( C = x + 2y \)[/tex] is [tex]\( 12.2 \)[/tex].