Gary is 8 years older than his brother. Six years ago Gary was three times as old as his brother. How old are they now?

Answer 1

g = b + 8

g - 6 = 3(b - 6)

Since g = b + 8, we can substitute b + 8 for g in the 2nd equation.

b + 8 - 6 = 3b - 18

2b = 20

b = 10

g = 10 + 8

g = 18