SOLUTION: sean is 20 and his brother is 12. how many years ago was sean three times as old as his brother?

Question 1030156: sean is 20 and his brother is 12. how many years ago was sean three times as old as his brother?
Answer by Cromlix(4381) (Show Source): You can put this solution on YOUR website!
Hi there,
n = number of years ago that
Sean was 3 times his brother.
20 - n = 3*(12 - n)
20 - n = 36 - 3n
Colect like terms:
-n + 3n = 36 - 20
2n = 16
n = 8
It was 8 years ago when
Sean was three times his
brother's age.
Sean was 20 - 8 = 12
His brother was 12 - 8 = 4.
Hope this helps :-)
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