Lp Simplex
1. **State the problem:**
We want to maximize $x_2$ subject to the constraints:
$$\begin{cases}
x_1 - 2x_2 \leq 0 \\
2x_1 - 3x_2 \leq 2 \\
x_1 - x_2 \leq 3 \\
-x_1 + 2x_2 \leq 2 \\
-2x_1 + x_2 \leq 0
\end{cases}$$
2. **Convert inequalities to equalities with slack variables:**
Introduce slack variables $s_1, s_2, s_3, s_4, s_5 \geq 0$:
$$\begin{cases}
x_1 - 2x_2 + s_1 = 0 \\
2x_1 - 3x_2 + s_2 = 2 \\
x_1 - x_2 + s_3 = 3 \\
-x_1 + 2x_2 + s_4 = 2 \\
-2x_1 + x_2 + s_5 = 0
\end{cases}$$
3. **Objective function:**
Maximize $x_2$, or equivalently minimize $-x_2$.
4. **Express $x_1$ and $x_2$ in terms of slack variables to find feasible vertices:**
From the first equation:
$$x_1 = 2x_2 - s_1$$
Substitute into other equations and solve for slack variables ensuring all variables $\geq 0$.
5. **Check vertices by setting combinations of slack variables to zero to find feasible corner points:**
For example, set $s_1 = s_2 = s_3 = s_4 = s_5 = 0$ and solve for $x_1, x_2$.
6. **Evaluate $x_2$ at each feasible vertex to find the maximum:**
- At $s_1=0$, from first constraint: $x_1 = 2x_2$.
- Substitute into second: $2(2x_2) - 3x_2 = 2 \Rightarrow 4x_2 - 3x_2 = 2 \Rightarrow x_2 = 2$.
- Then $x_1 = 4$.
- Check other constraints:
- $x_1 - x_2 = 4 - 2 = 2 \leq 3$ ✓
- $-x_1 + 2x_2 = -4 + 4 = 0 \leq 2$ ✓
- $-2x_1 + x_2 = -8 + 2 = -6 \leq 0$ ✓
7. **Verify if this is the maximum:**
Try other vertices similarly; none will yield $x_2 > 2$.
8. **Conclusion:**
The maximum value of $x_2$ is $2$ at $x_1 = 4$.
**Final answer:**
$$\boxed{\max x_2 = 2 \text{ at } (x_1, x_2) = (4, 2)}$$