Question 994189

suppose Peter is now {{{x}}} years old

if John is {{{12}}} years older than his brother Peter, then John is {{{x+12}}} 

four years ago Peter was {{{x-4}}} years

if John was three times as old as Peter was then,then John is {{{3*(x+12-4)=3(x+8)}}}


so, your answer is: [3] Four years ago {{{(x -4) = 3(x + 8)}}}