The graphical method of LP problem uses :

Options

A. Objective function equations
B. Constraint equation
C. Linear equations
D. All of the above

Answer

To solve the question regarding the graphical method of Linear Programming (LP) problems, we can break down the solution into clear steps:

### Step-by-Step Solution:

1. **Understanding Linear Programming (LP)**:
- Linear Programming (LP) is a mathematical method for determining a way to achieve the best outcome in a given mathematical model. It involves the optimization of a linear objective function, subject to linear equality and inequality constraints.

**Hint**: Remember that LP is about optimizing a function under certain constraints.

2. **Identifying the Graphical Method**:
- The graphical method is a way to visualize the feasible region defined by the constraints of the LP problem. It is particularly useful when dealing with two variables, as it allows us to plot the constraints on a graph.

**Hint**: Visualizing the problem can help in understanding the feasible region and the optimal solution.

3. **Types of Equations Used**:
- In the graphical method, we primarily use:
- **Linear inequalities**: These define the feasible region.
- **Objective function equations**: This is the function we aim to maximize or minimize.
- **Constant terms**: These are the specific values in the equations that help in plotting the lines on the graph.

**Hint**: The constraints and the objective function are both linear, which is crucial for the graphical method.

4. **Conclusion**:
- Therefore, the graphical method of LP problems uses linear inequalities, objective function equations, and constant terms. Hence, the correct answer to the question is "All of the above".

**Hint**: When faced with multiple choices, consider if all options can be correct based on the context.

### Final Answer:
The graphical method of LP problem uses linear inequalities, objective function equations, and constant terms. Thus, the answer is "All of the above".