Solve the following linear programming problem graphically:
Minimize: `z=x+3y`
Subject to:
`x+yle8`
`3x+5yge15`
`xge0`
`yge0`

Explanation

To solve the given linear programming problem graphically, we will follow these steps:

### Step 1: Define the Objective Function and Constraints
We need to minimize the objective function:
\[ z = x + 3y \]

Subject to the constraints:
1. \( x + y \leq 8 \)
...