Question 12059
Their current ages:
Vincent=3x
Vin's Bro=x



their ages six years ago:
Vincent=3x-6
Vin's Bro=x-6
(3x-6)+(x-6)=3x
4x-12=3x
x=12




x=12-->Vincent's brother is 12 years old.
3x=36       -->Vincent is 36 years old.


Check: 
(36-6)+(12-6)=36
30+6=36