If the ages of the three brothers are consecutive even integers, then their ages differ by 2 years each.

Let x be the age of the youngest brother. Then the age of the next brother must be two years more --- x + 2. And the age of the oldest must be two more -- x + 4.

Your problem then says that three times the age of the youngest brother (3 times x) exceeds (subtract) the age of the oldest brother (x + 4) by 48 years.

Your equation then is 3x - (x + 4) = 48 [Note: Since you are subtracting the entire age of the older brother, you need the parentheses.]

Your equation is ready to be solved. I hope this helped.