Step 1: Define the constraints.
The constraints on the number of articles are based on the total cost and the earnings. The inequality \( 4x + 3y \leq 24 \) ensures that the total cost does not exceed the limit.
Step 2: Conclusion.
The linear constraints are \( x \geq 0, y \geq 0, 4x + 3y \leq 24 \).
Final Answer:
\[
\boxed{x \geq 0, y \geq 0, 4x + 3y \leq 24}
\]