Answer: there is no solution.
Explanation:
Let x represent my age.
Let y represent my brother's age.
Donald says that my age is three years less than three fourths of my brothers age. This means that
x = 3y/4 - 3
Denise says that my age is one year more than three fourths of my brother’s age.. This means that
x = 3y/4 + 1
3y/4 - 3 = 3y/4 + 1
Multiplying through by 4, it becomes
3y - 12 = 3y + 4
3y - 3y = 4 + 12
0 = 16
Therefore, there is no solution.