1. **State the problem:**
We want to maximize the objective function $$Z = 3X + 5Y$$ subject to the constraints:
$$3X + 5Y \leq 100$$
$$8X + 6Y \leq 80$$
with $$X \geq 0$$ and $$Y \geq 0$$.
2. **Identify the feasible region:**
The feasible region is defined by the inequalities above. We will find the corner points by solving the system of equations formed by the constraints.
3. **Find intercepts for each constraint:**
- For $$3X + 5Y = 100$$:
- When $$X=0$$, $$5Y=100 \Rightarrow Y=20$$.
- When $$Y=0$$, $$3X=100 \Rightarrow X=\frac{100}{3} \approx 33.33$$.
- For $$8X + 6Y = 80$$:
- When $$X=0$$, $$6Y=80 \Rightarrow Y=\frac{80}{6} = \frac{40}{3} \approx 13.33$$.
- When $$Y=0$$, $$8X=80 \Rightarrow X=10$$.
4. **Find intersection point of the two constraints:**
Solve the system:
$$\begin{cases} 3X + 5Y = 100 \\ 8X + 6Y = 80 \end{cases}$$
Multiply the first equation by 6 and the second by 5 to eliminate $$Y$$:
$$\begin{cases} 18X + 30Y = 600 \\ 40X + 30Y = 400 \end{cases}$$
Subtract the first from the second:
$$40X + 30Y - (18X + 30Y) = 400 - 600$$
$$22X = -200$$
$$X = \frac{-200}{22} = -\frac{100}{11} \approx -9.09$$
Since $$X$$ cannot be negative, the intersection is outside the feasible region.
5. **Evaluate $$Z$$ at corner points of the feasible region:**
- At $$X=0, Y=0$$:
$$Z = 3(0) + 5(0) = 0$$
- At $$X=0, Y=13.33$$ (from second constraint):
$$Z = 3(0) + 5(13.33) = 66.67$$
- At $$X=10, Y=0$$ (from second constraint):
$$Z = 3(10) + 5(0) = 30$$
- At $$X=\frac{100}{3} \approx 33.33, Y=0$$ (from first constraint):
$$Z = 3(33.33) + 5(0) = 100$$
- At $$X=0, Y=20$$ (from first constraint):
$$Z = 3(0) + 5(20) = 100$$
6. **Check feasibility of points:**
- Point $$X=\frac{100}{3}, Y=0$$ satisfies:
$$8(33.33) + 6(0) = 266.64 > 80$$ (not feasible)
- Point $$X=0, Y=20$$ satisfies:
$$8(0) + 6(20) = 120 > 80$$ (not feasible)
- Point $$X=0, Y=13.33$$ satisfies:
$$3(0) + 5(13.33) = 66.65 \leq 100$$ and $$8(0) + 6(13.33) = 80$$ (feasible)
- Point $$X=10, Y=0$$ satisfies:
$$3(10) + 5(0) = 30 \leq 100$$ and $$8(10) + 6(0) = 80$$ (feasible)
- Point $$X=0, Y=0$$ is trivially feasible.
7. **Check points on the line segment between $$X=10, Y=0$$ and $$X=0, Y=13.33$$:**
Since the intersection of constraints is not feasible, the maximum lies on the line segment between these two points.
8. **Calculate $$Z$$ at these points:**
- At $$X=10, Y=0$$: $$Z=30$$
- At $$X=0, Y=13.33$$: $$Z=66.67$$
9. **Conclusion:**
The maximum value of $$Z$$ under the constraints is approximately $$66.67$$ at $$X=0, Y=\frac{40}{3}$$.
**Final answer:**
$$X=0, Y=\frac{40}{3} \approx 13.33, \quad Z_{max} = 66.67$$
Linear Programming 7D28B7
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