A company produces two types of electronics: tablets and laptops. The production of laptops is represented by the variable l and the production of tablets is represented by t. The factory has the following constraints:
- Each laptop requires 4 units of raw material and each tablet requires 2 units.
- The total available raw material is 280 units.
- Additionally, the factory can produce a maximum of 50 laptops.
The company wants to maximize its output of electronics. If the company produces l laptops and t tablets, which equation represents the constraints on the production limits based on the material available?