The sum of the ages of two brothers is 38. Four years ago the age of the elder brother was square that of the younger brother. What are the ages of the two brothers?
4 years ago, each brother would have been 4 years younger.
That means that the sum of their ages would have been 8 less than the sum of therir ages now. (8 = 2 * 4)
So, 8 years ago the sum of their ages would gave been 30.
The only two numbers, where one of them is the square of the other, and fit in this range, are 5 and 25.
The ages of the brothers are: 9 yrs and 29 yrs