Final answer:
The inequality to represent Jorge and his brother's age situation is x + (x - 1) >= 25, which simplifies to x >= 13. Hence, the youngest age Jorge's brother can be is 13 years old.
Step-by-step explanation:
The situation described in the question can be represented by the following inequality
Let x represent Jorge's brother's age. Because Jorge is 1 year younger than his brother, Jorge's age is x - 1. The sum of their ages is at least 25 years. Therefore, we can write the inequality as x + (x - 1) ≥ 25.
Simplifying this inequality:
The youngest age Jorge's brother can be is 13 since if he were younger, the total age would not be at least 25.